allenai/sciq · Datasets at Hugging Face

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The presence of what in leaf cells makes most leaves appear green?	carbonate	hydrogen	sodium	chlorophyll	30.4 \| Leaves By the end of this section, you will be able to: • Identify the parts of a typical leaf • Describe the internal structure and function of a leaf • Compare and contrast simple leaves and compound leaves • List and describe examples of modified leaves Leaves are the main sites for photosynthesis: the process by which plants synthesize food. Most leaves are usually green, due to the presence of chlorophyll in the leaf cells. However, some leaves may have different colors, caused by other plant pigments that mask the green chlorophyll. The thickness, shape, and size of leaves are adapted to the environment. Each variation helps a plant species maximize its chances of survival in a particular habitat. Usually, the leaves of plants growing in tropical rainforests have larger surface areas than those of plants growing in deserts or very cold conditions, which are likely to have a smaller surface area to minimize water loss.
What is the name of the project concerning genetics that is one of the landmark scientific events of the last 50 years?	blue beam project	human organism project	manhattan project	human genome project	Beginning with Mendel's pea plants, genetics has become one of the most important fields of biology. Genetics discusses genetics, from Mendel's pea plants to current ethical issues associated with this field. The completion of The Human Genome Project is one of the landmark scientific events of the last 50 years. Human genetics affects many, if not every, field of medicine. Technologies associated with genetics are involved in developing products to make our lives better, but have raised a number of ethical, legal and social issues.
Wind is one method for dispersal of what, ensuring a new generation?	eggs	dust	clouds	seeds
Most ecosystems are disturbed too often to attain what final, stable status?	even community	undisrupted community	calm community	climax community	Most ecosystems are disturbed too often to attain a final, stable climax community.
What kind of diet is typical for raptors, such as hawks and owls?	herbivorous	fishes	carnivorous or herbivorous	carnivorous	Raptors such as hawks and owls are carnivores. They hunt and eat mammals and other birds. Vultures are scavengers . They eat the remains of dead animals, such as roadkill. Aquatic birds generally eat fish or water plants. Perching birds may eat insects, fruit, honey, or nectar. Many fruit-eating birds play a key role in seed dispersal, and some nectar-feeding birds are important pollinators .
The most basic division of land plants is between what type of plants?	succulents and conifers	perennial and annual	deciduous and evergreen	nonvascular and vascular	The scientific classification of modern land plants is under constant revision. Informally, land plants can be classified into the groups listed in Table below . The most basic division is between nonvascular and vascular plants. Vascular plants are further divided into those that reproduce without seeds and those that reproduce with seeds. Seed plants, in turn, are divided into those that produce seeds in cones and those that produce seeds in the ovaries of flowers. You can read more about each of these groups of plants in the next lesson.
What do vaccines produce to combat viral diseases?	hyperthyroidism	sterility	sensitivity	immunity	The study of viruses is known as virology and people who study viruses are known as virologists . Viruses infect and live inside the cells of living organisms. When viruses infect the cells of their host, they may cause disease. For example, viruses cause AIDS (Acquired immune deficiency syndrome), influenza (flu), chicken pox, and the common cold. Therapy is sometimes difficult for viral diseases. Antibiotics have no effect on viruses and only a few antiviral drugs are available for some diseases. One of the best ways to prevent viral diseases is with a vaccine , which produces immunity . But vaccines are available for only a few diseases.
Internal functions are coordinated and regulated so that the internal environment of a living thing is relatively constant, referred to as what?	homogenesis	stabilizer	hypothesis	homeostasis	Biology - The Life Science • Internal functions are coordinated and regulated so that the internal environment of a living thing is relatively constant, referred to as homeostasis10 . Living things are organized in the microscopic level from atoms up to cells11 . Atoms are arranged into molecules, then into macromolecules12 , which make up organelles13 , which work together to form cells. Beyond this, cells are organized in higher levels to form entire multicellular organisms. Cells together form tissues14 , which make up organs, which are part of organ systems, which work together to form an entire organism. Of course, beyond this, organisms form populations which make up parts of an ecosystem. All of the Earth's ecosystems together form the diverse environment that is the earth. Example:sub atoms, atoms, molecules, cells, tissues, organs, organ systems, organisms, population, community, eco systems.
What is a long, tube-shaped bundle of neurons, protected by the vertebrae?	a dendrite	a ganglion	an axon	the spinal cord	The spinal cord is a long, tube-shaped bundle of neurons, protected by the vertebrae. It runs from the brain stem to the lower back. The main job of the spinal cord is to carry nerve impulses back and forth between the body and brain. The spinal cord is like a two-way highway. Messages about the body, both inside and out, pass through the spinal cord to the brain. Messages from the brain pass in the other direction through the spinal cord to tell the body what to do.
What does the kelvin scale measure?	precipitation	height	oxygen	temperature	The SI scale for measuring temperature is the Kelvin scale . However, some scientists use the Celsius scale instead. If you live in the U. S. , you are probably more familiar with the Fahrenheit scale. Table below compares all three temperature scales. What is the difference between the boiling and freezing points of water on each of these scales?.
Ash that enters the air naturally as a result of a volcano eruption is classified as what kind of pollutant?	natural pollutant	thick pollutant	secondary pollutant	primary pollutant	Primary pollutants enter the air directly. Some are released by natural processes, like ash from volcanoes. Most are released by human activities. They pour into the air from vehicles and smokestacks. Several of these pollutants are described below.
What happens when an increase in temperature of a gas in a rigid container happens?	container shrinks	gas explodes	pressure decreases	pressure increases	An increase in temperature of a gas in a rigid container increases the pressure.
Which reaction between alkyl halides and ammonia makes alkylamines?	nucleophobic reactions	nitrogen catabolism	conductive substitution reactions	nucleophilic substitution reactions	molecular masses. Primary amines tend to have boiling points intermediate between those of the corresponding alcohol and alkane. Moreover, secondary and tertiary amines have lower boiling points than primary amines of comparable molecular mass. Tertiary amines form cations analogous to the ammonium ion (NH 4+), in which all four H atoms are replaced by alkyl groups. Such substances, calledquaternary ammonium salts, can be chiral if all four substituents are different. (Amines with three different substituents are also chiral because the lone pair of electrons represents a fourth substituent. ) Alkylamines can be prepared by nucleophilic substitution reactions of alkyl halides with ammonia or other amines: Equation 24.12.
Genes are organized to make the control of gene expression easier. the promoter region is immediately upstream of this?	signalling sequence	propagate sequence	organic sequence	coding sequence	The Promoter and the Transcription Machinery Genes are organized to make the control of gene expression easier. The promoter region is immediately upstream of the coding sequence. This region can be short (only a few nucleotides in length) or quite long (hundreds of nucleotides long). The longer the promoter, the more available space for proteins to bind. This also adds more control to the transcription process. The length of the promoter is gene-specific and can differ dramatically between genes. Consequently, the level of control of gene expression can also differ quite dramatically between genes. The purpose of the promoter is to bind transcription factors that control the initiation of transcription. Within the promoter region, just upstream of the transcriptional start site, resides the TATA box. This box is simply a repeat of thymine and adenine dinucleotides (literally, TATA repeats). RNA polymerase binds to the transcription initiation complex, allowing transcription to occur. To initiate transcription, a transcription factor (TFIID) is the first to bind to the TATA box. Binding of TFIID recruits other transcription factors, including TFIIB, TFIIE, TFIIF, and TFIIH to the TATA box. Once this complex is assembled, RNA polymerase can bind to its upstream sequence. When bound along with the transcription factors, RNA polymerase is phosphorylated. This releases part of the protein from the DNA to activate the transcription initiation complex and places RNA polymerase in the correct orientation to begin transcription; DNA-bending protein brings the enhancer, which can be quite a distance from the gene, in contact with transcription factors and mediator proteins (Figure 16.9).
Which phylum is made up of segmented worms such as earthworms?	nematoda	chordata	arthropod	annelida	The phylum Annelida is made up of segmented worms such as earthworms. Segmented worms are divided into many repeating segments. There are roughly 15,000 species of annelids. Most belong to one of three classes. A species in each class is pictured in Figure below .
What is the transfer of thermal energy between substances called?	Radiation	Permeation	Diffusion	heat	Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature.
What functional units of chromosomes determine specific characteristics by coding for specific proteins?	cells	chromosomes	DNA	genes	Matched pairs of chromosomes in a diploid organism are called homologous (“same knowledge”) chromosomes. Homologous chromosomes are the same length and have specific nucleotide segments called genes in exactly the same location, or locus. Genes, the functional units of chromosomes, determine specific characteristics by coding for specific proteins. Traits are the variations of those characteristics. For example, hair color is a characteristic with traits that are blonde, brown, or black. Each copy of a homologous pair of chromosomes originates from a different parent; therefore, the genes themselves are not identical. The variation of individuals within a species is due to the specific combination of the genes inherited from both parents. Even a slightly altered sequence of nucleotides within a gene can result in an alternative trait. For example, there are three possible gene sequences on the human chromosome that code for blood type: sequence A, sequence B, and sequence O. Because all diploid human cells have two copies of the chromosome that determines blood type, the blood type (the trait) is determined by which two versions of the marker gene are inherited. It is possible to have two copies of the same gene sequence on both homologous chromosomes, with one on each (for example, AA, BB, or OO), or two different sequences, such as AB. Minor variations of traits, such as blood type, eye color, and handedness, contribute to the natural variation found within a species. However, if the entire DNA sequence from any pair of human homologous chromosomes is compared, the difference is less than one percent. The sex chromosomes, X and Y, are the single exception to the rule of homologous chromosome uniformity: Other than a small amount of homology that is necessary to accurately produce gametes, the genes found on the X and Y chromosomes are different.
Aside from light, incandescent light bulbs also give off what that wastes energy?	electricity	temperature	humidity	heat	The classroom in Figure above has artificial light sources in addition to natural sunlight. There are fluorescent lights on the ceiling of the room. There are also projectors on the ceiling that are shining light on screens. In these and most other artificial light sources, electricity provides the energy and some type of light bulb converts the electrical energy to visible light. How a light bulb produces visible light varies by type of bulb, as you can see in Table below . Incandescent light bulbs, which produce light by incandescence, give off a lot of heat as well as light, so they waste energy. Other light bulbs produce light by luminescence, so they produce little if any heat. These light bulbs use energy more efficiently. Which types of light bulbs do you use?.
What is an alpha particle with two protons and two neutrons called?	hydrogen nucleus	chloride nucleus	hydrogen nucleus	helium nucleus	In alpha decay, energy and an alpha particle are emitted by a nucleus that is unstable because it has too many protons. An alpha particle consists of two protons and two neutrons, so it is actually a helium nucleus.
Just as the reaction of a diol and a diacid forms a polyester, the reaction of a diacid and a diamine yields this?	acetone	phenol	polyethylene	polyamide	Polyamides Just as the reaction of a diol and a diacid forms a polyester (Section 15.8 "Preparation of Esters"), the reaction of a diacid and a diamine yields a polyamide. The two difunctional monomers often employed are adipic acid and 1,6-hexanediamine. The monomers condense by splitting out water to form a new product, which is still difunctional and thus can react further to yield a polyamide polymer.
Structural rearrangements of what include partial duplications, deletions, inversions, and translocations; duplications and deletions often produce offspring that survive but exhibit physical and mental abnormalities?	cells	neutrons	phenotypes	chromosomes	Chromosome Structural Rearrangements Cytologists have characterized numerous structural rearrangements in chromosomes, including partial duplications, deletions, inversions, and translocations. Duplications and deletions often produce offspring that survive but exhibit physical and mental abnormalities. Cri-du-chat (from the French for “cry of the cat”) is a syndrome associated with nervous system abnormalities and identifiable physical features that results from a deletion of most of the small arm of chromosome 5 (Figure 7.11). Infants with this genotype emit a characteristic high-pitched cry upon which the disorder’s name is based.
The e. coli chromosome, like many other bacterial chromosomes, is what shape?	triangular	oval	square	circular
What is the force of attraction between two masses?	momentum	electricity	inertia	gravity	Gravity is traditionally defined as a force of attraction between two masses. Weight measures the force of gravity and is expressed in newtons (N).
Chordates include vertebrates and invertebrates that have what?	a phloem	chordate	a endoderm	a notochord	Chordates include vertebrates and invertebrates that have a notochord.
Nearly how many millions of people die yearly due to air pollution?	eight million	two million	fifty million	five million	Almost 5 million people die each year because of air pollution. In fact, polluted air causes more deaths than traffic accidents. Air pollution harms the respiratory and circulatory systems. Both outdoor and indoor air can be polluted.
What instrument is used to record the length and strength of an earthquake?	microscope	transmitter	epicenter	seismograph	Earthquakes may take place every day near a volcano. But before an eruption the number and size of earthquakes increases. This is the result of magma pushing upward into the magma chamber. This motion causes stresses on neighboring rock to build up. Eventually the ground shakes. A continuous string of earthquakes may indicate that a volcano is about to erupt. Scientists use seismographs to record the length and strength of each earthquake.
Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only do what?	expand	vibrate	pull	contract	Muscles can only contract. They can’t actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure below . When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm.
What type of molecules are secreted by the cell in local signaling?	sleeping molecules	word molecules	negaitive molecules	messenger molecules
Pulmonary ventilation in mammals occurs via what?	ingestion	inflammation	osmosis	inhalation	Mammalian Systems In mammals, pulmonary ventilation occurs via inhalation (breathing). During inhalation, air enters the body through the nasal cavity located just inside the nose (Figure 39.7). As air passes through the nasal cavity, the air is warmed to body temperature and humidified. The respiratory tract is coated with mucus to seal the tissues from direct contact with air. Mucus is high in water. As air crosses these surfaces of the mucous membranes, it picks up water. These processes help equilibrate the air to the body conditions, reducing any damage that cold, dry air can cause. Particulate matter that is floating in the air is removed in the nasal passages via mucus and cilia. The processes of warming, humidifying, and removing particles are important protective mechanisms that prevent damage to the trachea and lungs. Thus, inhalation serves several purposes in addition to bringing oxygen into the respiratory system.
Chemical signals are received by the target cell on what?	parent proteins	acidic proteins	inceptor proteins	receptor proteins	The target cell then needs to be able to recognize the signal. Chemical signals are received by the target cell on receptor proteins. Most receptor proteins are found associated with the plasma membrane, but some are also found inside the cell. Receptor proteins are very specific for only one particular signal molecule, much like a lock that recognizes only one key. Therefore, a cell has lots of receptor proteins to recognize the large number of cell signal molecules. There are three stages to sending and receiving a cell "message:" reception, transduction, and response.
What kind of organisms are prokaryotes?	multicellular organisms	viral	single - flagellated	single-celled	All prokaryotes are single-celled organisms.
What act like filters and remove pathogens from lymph?	electric nodes	spine nodes	tissue nodes	lymph nodes	Before lymph reaches the bloodstream, it passes through small oval structures called lymph nodes, which are located along the lymph vessels. Figure below shows where some of the body’s many lymph nodes are concentrated. Lymph nodes act like filters and remove pathogens from lymph.
What are the primary cells of adaptive immune response?	white blood cells	erythrocytes	red blood cells	lymphocytes	Lymphocytes: B Cells, T Cells, Plasma Cells, and Natural Killer Cells As stated above, lymphocytes are the primary cells of adaptive immune responses (Table 21.1). The two basic types of lymphocytes, B cells and T cells, are identical morphologically with a large central nucleus surrounded by a thin layer of cytoplasm. They are distinguished from each other by their surface protein markers as well as by the molecules they secrete. While B cells mature in red bone marrow and T cells mature in the thymus, they both initially develop from bone marrow. T cells migrate from bone marrow to the thymus gland where they further mature. B cells and T cells are found in many parts of the body, circulating in the bloodstream and lymph, and residing in secondary lymphoid organs, including the spleen and lymph nodes, which will be described later in this section. The human body contains approximately 10 12 lymphocytes.
What term refers to the friction of fluid, within itself and its surroundings?	salinity	elasticity	volume	viscosity	12.4 Viscosity and Laminar Flow; Poiseuille’s Law Laminar Flow and Viscosity When you pour yourself a glass of juice, the liquid flows freely and quickly. But when you pour syrup on your pancakes, that liquid flows slowly and sticks to the pitcher. The difference is fluid friction, both within the fluid itself and between the fluid and its surroundings. We call this property of fluids viscosity. Juice has low viscosity, whereas syrup has high viscosity. In the previous sections we have considered ideal fluids with little or no viscosity. In this section, we will investigate what factors, including viscosity, affect the rate of fluid flow. The precise definition of viscosity is based on laminar, or nonturbulent, flow. Before we can define viscosity, then, we need to define laminar flow and turbulent flow. Figure 12.10 shows both types of flow. Laminar flow is characterized by the smooth flow of the fluid in layers that do not mix. Turbulent flow, or turbulence, is characterized by eddies and swirls that mix layers of fluid together.
What do you call a unique substance formed when two or more elements combine chemically?	solution	component	mixture	compound	Compounds are unique substances that form when two or more elements combine chemically. The smallest particles of compounds are molecules. Some compounds form crystals instead.
Caves form over time when what causes rocks like limestone to dissolve?	air	weather	acid	water	It can be really exciting to explore a big underground cave like the one in this picture. Do you know how caves form? Believe it or not, water is the answer. Water slowly dissolves rocks, especially certain types of rocks such as limestone. How does something as mild and harmless as water cause hard rocks to dissolve? In this chapter, you’ll find out.
Cycloalkanes are hydrocarbons whose molecules are closed rings rather than straight or branched chains. a cyclic hydrocarbon is a hydrocarbon with a ring of these?	barium atoms	oxygen atoms	hydrogen atoms	carbon atoms	Cycloalkanes are hydrocarbons whose molecules are closed rings rather than straight or branched chains. A cyclic hydrocarbon is a hydrocarbon with a ring of carbon atoms.
Speciation, convergent evolution, and coevolution are types of what process?	microevolution	devolution	systemic evolution	macroevolution	Macroevolution occurs when microevolution takes place over a long period of time. Types of macroevolution include speciation, convergent evolution, and coevolution.
In what state do ionic compounds best conduct electricity?	plasma	gas	solid	liquid	Solid ionic compounds are poor conductors of electricity. The strong bonds between ions lock them into place in the crystal. However, in the liquid state, ionic compounds are good conductors of electricity. Most ionic compounds dissolve easily in water. When they dissolve, they separate into individual ions. The ions can move freely, so they are good conductors of electricity. Dissolved ionic compounds are called electrolytes.
What type of protein fibers in the cytoskeleton are the narrowest?	capillaries	macrophages	mitosis	microfilaments	Microfilaments Of the three types of protein fibers in the cytoskeleton, microfilaments are the narrowest. They function in cellular movement, have a diameter of about 7 nm, and are made of two intertwined strands of a globular protein called actin (Figure 4.23). For this reason, microfilaments are also known as actin filaments.
Which layer of the earth is molten?	the mantle	the inner core	the metallic core	the outer core	The dense, iron core forms the center of the Earth. Scientists know that the core is metal. The inner core is solid, and the outer core is molten. Here are some of the reasons they know this:.
What is the general name for a solid material that is formed via a natural process?	plasma	chemical	gas	mineral	A mineral is a solid material that forms by a natural process. A mineral can be made of an element or a compound. It has a specific chemical composition. Its chemical composition is different from other minerals. Each type of mineral has physical properties that differ from others. These properties include crystal structure, hardness, density, and color. For example, silver is a soft, shiny metal. Salt is a white, cube-shaped crystal. Diamond is an extremely hard, translucent crystal.
In a photosystem, pigments in the light-harvesting complex pass light energy to two special molecules of what in the reaction center?	nutrient	calcium	carbonate	chlorophyll	Figure 8.15 A photosystem consists of a light-harvesting complex and a reaction center. Pigments in the lightharvesting complex pass light energy to two special chlorophyll a molecules in the reaction center. The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor. The excited electron must then be replaced. In (a) photosystem II, the electron comes from the splitting of water, which releases oxygen as a waste product. In (b) photosystem I, the electron comes from the chloroplast electron transport chain discussed below.
What branch of science is the study of matter and energy?	negative science	unnatural science	natural science	physical science	Physical science is the study of matter and energy. That covers a lot of territory because matter refers to all the “stuff” that exists in the universe. It includes everything you can see and many things that you cannot see, including the air around you. Energy is also universal. It’s what gives matter the ability to move and change. Electricity, heat, and light are some of the forms that energy can take.
What make us sick when they become human parasites?	larvae	detritus	viruses	protozoa	Most protist diseases in humans are caused by animal-like protists, or protozoa. Protozoa make us sick when they become human parasites. Three examples of parasitic protozoa are described below.
The tendency of an object to resist a change in its motion is called?	friction	gravitation	magnetism	inertia	Inertia is the tendency of an object to resist a change in its motion. The inertia of an object depends on its mass. Objects with greater mass have greater inertia. To overcome inertia, an unbalanced force must be applied to an object.
Contributing to the blood-brain barrier is one of the jobs of glial cells, which support neurons in what system?	digestive system	peripheral nervous system	circulatory system	central nervous system	Glial Cells of the CNS One cell providing support to neurons of the CNS is the astrocyte, so named because it appears to be star-shaped under the microscope (astro- = “star”). Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). Those processes extend to interact with neurons, blood vessels, or the connective tissue covering the CNS that is called the pia mater (Figure 12.11). Generally, they are supporting cells for the neurons in the central nervous system. Some ways in which they support neurons in the central nervous system are by maintaining the concentration of chemicals in the extracellular space, removing excess signaling molecules, reacting to tissue damage, and contributing to the blood-brain barrier (BBB). The blood-brain barrier is a physiological barrier that keeps many.
During the condensation reaction of sugars what is removed, linking the two sugars?	air	hormones	chlorophyll	water	The simple sugars form the foundation of more complex carbohydrates. The cyclic forms of two sugars can be linked together by means of a condensation reaction. The figure below shows how a glucose molecule and a fructose molecule combine to form a sucrose molecule. A hydrogen atom from one molecule and a hydroxyl group from the other molecule are eliminated as water, with a resulting covalent bond linking the two sugars together at that point.
What develops into embryos inside seeds, from which the next sporophyte generation grows?	pupa	secretions	buds	zygotes	In seed plants, the gametophyte generation takes place in a cone or flower, which forms on the mature sporophyte plant. Each male gametophyte is just a few cells inside a grain of pollen. Each female gametophyte produces an egg inside an ovule. Pollination must occur for fertilization to take place. Zygotes develop into embryos inside seeds, from which the next sporophyte generation grows.
A change in temperature with distance is called a what?	solution gradient	oxygen gradient	speed gradient	temperature gradient	Air temperature changes with altitude. This does not occur in the same way as pressure and density, which decrease with altitude. Changes in air temperature are not regular. A change in temperature with distance is called a temperature gradient .
What sac, which was sitting on top of the flat embryo, envelops the embryo as it folds?	epithelial sac	uterus	umbilical sac	amniotic sac	The embryo, which begins as a flat sheet of cells, begins to acquire a cylindrical shape through the process of embryonic folding (Figure 28.14). The embryo folds laterally and again at either end, forming a C-shape with distinct head and tail ends. The embryo envelops a portion of the yolk sac, which protrudes with the umbilical cord from what will become the abdomen. The folding essentially creates a tube, called the primitive gut, that is lined by the endoderm. The amniotic sac, which was sitting on top of the flat embryo, envelops the embryo as it folds.
Catecholamines are a class of amine hormones synthesised form which amino acid?	phenylalanine	epinephrine	dopamine	tyrosine
Regulation of hormone production hormone levels are primarily controlled through negative feedback, in which rising levels of a hormone inhibit its?	Limited release	particular release	recent release	further release	37.4 Regulation of Hormone Production Hormone levels are primarily controlled through negative feedback, in which rising levels of a hormone inhibit its further release. The three mechanisms of hormonal release are humoral stimuli, hormonal stimuli, and neural stimuli. Humoral stimuli refers to the control of hormonal release in response to changes in extracellular fluid levels or ion levels. Hormonal stimuli refers to the release of hormones in response to hormones released by other endocrine glands. Neural stimuli refers to the release of hormones in response to neural stimulation.
Androgen secretion and sperm production are both controlled by hypothalamic and which other hormones?	adrenal	Testes	salivary	pituitary
The sum of the superscripts in an electron configuration is equal to the number of electrons in that atom, which is in turn equal to what number?	orbital number	metallic number	shell number	atomic number	Electron configuration notation eliminates the boxes and arrows of orbital filling diagrams. Each occupied sublevel designation is written followed by a superscript that is the number of electrons in that sublevel. For example, the hydrogen configuration is 1 s 1 , while the helium configuration is 1 s 2 . Multiple occupied sublevels are written one after another. The electron configuration of lithium is 1 s 2 2 s 1 . The sum of the superscripts in an electron configuration is equal to the number of electrons in that atom, which is in turn equal to its atomic number.
What part of the brain controls body position, coordination, and balance?	right brain	cerebrum	brain stem	cerebellum	The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeem’s cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance.
When light transfers its energy to objects, this is known as what?	condensation	accumulation	evaporation	absorption	Light may transfer its energy to matter rather than being reflected or transmitted by matter. This is called absorption . When light is absorbed, the added energy increases the temperature of matter. If you get into a car that has been sitting in the sun all day, the seats and other parts of the car’s interior may be almost too hot to touch, especially if they are black or very dark in color. That’s because dark colors absorb most of the sunlight that strikes them.
What do most amphibians breathe with as larvae?	nasal passages	pores	lungs	gills	Most amphibians breathe with gills as larvae and with lungs as adults. Additional oxygen is absorbed through the skin in most species. The skin is kept moist by mucus, which is secreted by mucous glands. In some species, mucous glands also produce toxins, which help protect the amphibians from predators. The golden frog shown in Figure below is an example of a toxic amphibian.
The chemical used by the ants to weed their garden turns out to be what kind?	sealant acid	sulfide acid	nitric acid	formic acid
A common age-related bone disease in which bone density and strength is decreased is know as what?	fibrosis	allergies	Stomach	osteoporosis	Osteoporosis is a common age-related bone disease in which bone density and strength is decreased. Watch this video (http://openstaxcollege. org/l/osteoporosis) to get a better understanding of how thoracic vertebrae may become weakened and may fracture due to this disease. How may vertebral osteoporosis contribute to kyphosis?.
Some fruit, like peaches, only have one big seed. what is this seed called?	the core	the middle	the seed	the pit
Dragonflies were one of the first insects to do what?	sexually reproduce	swim	fight	fly
Intestinal cells combine with proteins to create what?	lipoproteins	amino acids	chondrocytes	chylomicrons	Diffusion into intestinal cells, where they are combined with proteins to create chylomicrons.
Dutch elm trees used to be common, beautiful trees in the united states. now most of them have been killed by what?	cancer	carbon dioxide	beetles	dutch elm disease	Dutch elm trees used to be common, beautiful trees in the United States. Now most of them, like this tree, have been killed by Dutch elm disease. Dutch elm disease is caused by a fungus. This is just one example of how fungi can interact with other species.
Two major types of fungus-like protists are slime molds and which other?	black molds	foul molds	green molds	water molds	Fungus-like protists share many features with fungi. Like fungi, they are heterotrophs, meaning they must obtain food outside themselves. They also have cell walls and reproduce by forming spores, just like fungi. Fungus-like protists usually do not move, but a few develop movement at some point in their lives. Two major types of fungus-like protists are slime molds and water molds .
What are broken down during digestion to provide the amino acids needed for protein synthesis?	metabolytes	sugars	carbohydrates	dietary proteins	Dietary proteins are broken down during digestion to provide the amino acids needed for protein synthesis. Any extra proteins in the diet not needed for this purpose are used for energy or stored as fat. One gram of proteins provides 4 Calories of energy. Eating protein provides the amino acids for your cells to produce your own antibodies, muscle fibers and enzymes (as well as many other types of proteins).
A group of atoms that results when one hydrogen atom is removed from an alkane is referred to as what?	nitrate group	chloride group	hyrdrogen group	alkyl group	An alkyl group is a group of atoms that results when one hydrogen atom is removed from an alkane. The group is named by replacing the -ane suffix of the parent hydrocarbon with -yl. For example, the CH3 group derived from methane (CH4) results from subtracting one hydrogen atom and is called a methyl group. The alkyl groups we will use most frequently are listed in Table 12.4 "Common Alkyl Groups". Alkyl groups are not independent molecules; they are parts of molecules that we consider as a unit to name compounds systematically. Table 12.4 Common Alkyl Groups.
What is the term for stored energy that an object has due to its position or shape?	vertical energy	kinetic energy	mechanical energy	potential energy	A: Electric charges flow when they have electric potential energy. Potential energy is stored energy that an object has due to its position or shape.
What force is greater on rougher surfaces than smooth surfaces?	gravity	tension	acceleration	friction	Rougher surfaces have more friction between them than smoother surfaces. That’s why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. That’s why you can’t slide as far across ice with shoes as you can with skates (see Figure below ). The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction because they press together with greater force. Did you ever try to push boxes or furniture across the floor? It’s harder to overcome friction between heavier objects and the floor than it is between lighter objects and the floor.
Nitrogen is a very important element to living things, because it is part of nucleotides and amino acids that are the building blocks of nucleic acids and these?	follicles	cells	lipids	proteins	Cooperation between Bacteria and Eukaryotes: Nitrogen Fixation Nitrogen is a very important element to living things, because it is part of nucleotides and amino acids that are the building blocks of nucleic acids and proteins, respectively. Nitrogen is usually the most limiting element in terrestrial ecosystems, with atmospheric nitrogen, N2, providing the largest pool of available nitrogen. However, eukaryotes cannot use atmospheric, gaseous nitrogen to synthesize macromolecules. Fortunately, nitrogen can be “fixed,” meaning it is converted into ammonia (NH3) either biologically or abiotically. Abiotic nitrogen fixation occurs as a result of lightning or by industrial processes. Biological nitrogen fixation (BNF) is exclusively carried out by prokaryotes: soil bacteria, cyanobacteria, and Frankia spp. (filamentous bacteria interacting with actinorhizal plants such as alder, bayberry, and sweet fern). After photosynthesis, BNF is the second most important biological process on Earth. The equation representing the process is as follows.
In the mouth, enzymes present in what begin to chemically break down food?	lymph	blood	acid	saliva	The Human Digestive System The process of digestion begins in the mouth with the intake of food (Figure 16.4). The teeth play an important role in masticating (chewing) or physically breaking food into smaller particles. The enzymes present in saliva also begin to chemically break down food. The food is then swallowed and enters the esophagus—a long tube that connects the mouth to the stomach. Using peristalsis, or wave-like smooth-muscle contractions, the muscles of the esophagus push the food toward the stomach. The stomach contents are extremely acidic, with a pH between 1.5 and 2.5. This acidity kills microorganisms, breaks down food tissues, and activates digestive enzymes. Further breakdown of food takes place in the small intestine where bile produced by the liver, and enzymes produced by the small intestine and the pancreas, continue the process of digestion. The smaller molecules are absorbed into the blood stream through the epithelial cells lining the walls of the small intestine. The waste material travels on to the large intestine where water is absorbed and the drier waste material is compacted into feces; it is stored until it is excreted through the anus.
Unlike the cells of plants and fungi, animal cells lack what?	nuclei	mitochondria	flagella	cell wall	Like the cells of all eukaryotes, animal cells have a nucleus and other membrane-bound organelles (see Figure below ). Unlike the cells of plants and fungi, animal cells lack a cell wall. This gives animal cells flexibility. It lets them take on different shapes so they can become specialized to do particular jobs. The human nerve cell shown in Figure below is a good example. Its shape suits its function of transmitting nerve impulses over long distances. A nerve cell would be unable to take this shape if it were surrounded by a rigid cell wall.
Because alkali metals are so reactive, they are found in nature only in ________ with other elements?	competition	isolation	cooperation	combination	Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very “eager” to gain an electron. At the URL below, you can watch a video that shows just how reactive the alkali metals are.
What is the plane that divides the body or an organ vertically into right and left sides?	anatomical plane	median plane	parasagittal plane	sagittal plane	• The sagittal plane is the plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into unequal right and left sides, it is called a parasagittal plane or less commonly a longitudinal section. • The frontal plane is the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. The frontal plane is often referred to as a coronal plane. (“Corona” is Latin for “crown. ”) • The transverse plane is the plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.
What are the organs work together to allow us to see?	nose	lungs	heart	brain and eyes	The ability to see is called vision. The brain and eyes work together to allow us to see. The eyes collect and focus visible light and change it to electrical signals that travel to the brain. The brain interprets the signals and “tells” us what we are seeing.
The brain develops from this early tube structure and gives rise to specific regions of the adult brain. as the neural tube grows and differentiates, it enlarges into three vesicles that correspond to the forebrain, midbrain, and this?	astrobrain	anteriorbrain	rearbrain	hindbrain	into the brain, and the posterior region becomes the spinal cord. Tissues at the edges of the neural groove, when it closes off, are called the neural crest and migrate through the embryo to give rise to PNS structures as well as some non-nervous tissues. The brain develops from this early tube structure and gives rise to specific regions of the adult brain. As the neural tube grows and differentiates, it enlarges into three vesicles that correspond to the forebrain, midbrain, and hindbrain regions of the adult brain. Later in development, two of these three vesicles differentiate further, resulting in five vesicles. Those five vesicles can be aligned with the four major regions of the adult brain. The cerebrum is formed directly from the telencephalon. The diencephalon is the only region that keeps its embryonic name. The mesencephalon, metencephalon, and myelencephalon become the brain stem. The cerebellum also develops from the metencephalon and is a separate region of the adult brain. The spinal cord develops out of the rest of the neural tube and retains the tube structure, with the nervous tissue thickening and the hollow center becoming a very small central canal through the cord. The rest of the hollow center of the neural tube corresponds to open spaces within the brain called the ventricles, where cerebrospinal fluid is found.
Biotechnology uses what to solve problems?	geology	psycology	ecology	biology	Biotechnology is technology based on biological applications. These applications are increasingly used in medicine, agriculture and food science. Biotechnology combines many features of biology, including genetics, molecular biology, biochemistry, embryology, and cell biology. Many aspects of biotechnology center around DNA and its applications, otherwise known as DNA technology. We could devote a whole textbook to current applications of biotechnology, however, we will focus on the applications towards medicine and agriculture, and the extension into the forensic sciences. First, though, we need to understand DNA technology.
What are hurricanes called in the pacific?	twisters	tornados	rainstorms	typhoons	Tornadoes may also come from hurricanes. A hurricane ( Figure below ) is an enormous storm with high winds and heavy rains. Hurricanes may be hundreds of kilometers wide. They may travel for thousands of kilometers. The storm's wind speeds may be greater than 251 kilometers (156 miles) per hour. Hurricanes develop from tropical cyclones. Hurricanes are called typhoons in the Pacific.
What is the organ in which gas exchanges take place between blood and air?	kidney	heart	skin	lungs	Respiration begins with ventilation. This is the process of moving air in and out of the lungs. The lungs are the organs in which gas exchange takes place between blood and air.
What branch of science deals with the effects people have on the environment?	ecological science	physical science	cultural science	environmental science	Environmental science deals with the effects people have on the environment.
Sickle cell anemia is what type of disorder?	nongenetic disorder	autosomal dominant disorder	spontaneous mutation	autosomal recessive disorder	Sickle-Shaped and Normal Red Blood Cells. Sickle cell anemia is an autosomal recessive disorder. The mutation that causes the disorder affects just one amino acid in a single protein, but it has serious consequences for the affected person. This photo shows the sickle shape of red blood cells in people with sickle cell anemia.
Which region is just posterior to the mouth?	the diaphragm	the esophagus	the duodenum	the pharynx
What is the collective travel of sheep known as?	den	gaggle	load	herd	Like many other animals, sheep travel in herds. The tendency is for each individual sheep to stay with the herd. However, a sheep may sometimes wander off, depending on how strong the attraction is for a particular food or water supply. At other times, a sheep may become frightened and run off. Whether a sheep chooses to stay with the herd or go its own way depends on the balance between attraction to the herd and attraction to the outside influence.
What are these examples of: a person riding a carousel and a skydiver in free fall?	centripetal force	vibration	centrifugal force	acceleration	Examples of acceleration include a person riding a carousel and a skydiver in free fall.
Elements below the second period, such as silicon, do not form what as readily as second-period elements, and when they do form, they are weaker than those formed by second-period elements?	k. bonds	covalent bonds	magnetic bonds	n bonds	Silicon dioxide, silica, occurs in both crystalline and amorphous forms. The usual crystalline form of silicon dioxide is quartz, a hard, brittle, clear, colorless solid. It is useful in many ways—for architectural decorations, semiprecious jewels, and frequency control in radio transmitters. Silica takes many crystalline forms, or polymorphs, in nature. Trace amounts of Fe3+ in quartz give amethyst its characteristic purple color. The term quartz is also used for articles such as tubing and lenses that are manufactured from amorphous silica. Opal is a naturally occurring form of amorphous silica. The contrast in structure and physical properties between silicon dioxide and carbon dioxide is interesting, as illustrated in Figure 18.18. Solid carbon dioxide (dry ice) contains single CO2 molecules with each of the two oxygen atoms attached to the carbon atom by double bonds. Very weak intermolecular forces hold the molecules together in the crystal. The volatility of dry ice reflect these weak forces between molecules. In contrast, silicon dioxide is a covalent network solid. In silicon dioxide, each silicon atom links to four oxygen atoms by single bonds directed toward the corners of a regular tetrahedron, and SiO4 tetrahedra share oxygen atoms. This arrangement gives a three dimensional, continuous, silicon-oxygen network. A quartz crystal is a macromolecule of silicon dioxide. The difference between these two compounds is the ability of the group 14 elements to form strong π bonds. Secondperiod elements, such as carbon, form very strong π bonds, which is why carbon dioxide forms small molecules with strong double bonds. Elements below the second period, such as silicon, do not form π bonds as readily as secondperiod elements, and when they do form, the π bonds are weaker than those formed by second-period elements. For this reason, silicon dioxide does not contain π bonds but only σ bonds.
Through what method or methods of fertilization do amphibians sexually reproduce?	spawning or budding	asexual or sexual	mitosis and meiosis	external or internal	Amphibians reproduce sexually with either external or internal fertilization. They may attract mates with calls or scents. They do not produce amniotic eggs, so they must reproduce in water. Their larvae go through metamorphosis to change into the adult form.
The distance between corresponding points of adjacent waves is known as the __________	amplitude	absorption	bandwidth	wavelength	Wavelength is the distance between corresponding points of adjacent waves. Wavelengths of electromagnetic waves range from many kilometers to a tiny fraction of a millimeter.
Which system consists of all the nervous tissue that lies outside the central nervous system?	cerebral cortex	auxiliary nervous system	spinal cord	peripheral nervous system	The peripheral nervous system consists of all the nervous tissue that lies outside the central nervous system. It is connected to the central nervous system by nerves. It has several divisions and subdivisions that transmit nerve impulses between the central nervous system and the rest of the body.
What mechanism is used by living organisms to pass along genes?	chlorophyll	protein	digestion	dna	16 Gregor Mendel and biological inheritance Charles Darwin1 , for all he contributed to the science of biology, never knew about the mechanism by which living things inherit traits from previous generations, or how new traits arise. As any schoolchild can tell you, this mechanism of interitance has since been found to be DNA2 , or deoxyribonucleic acid. DNA allows for stable inheritance of traits: the code in each strand of DNA is replicated precisely through the pairing of basic units along each strand. The error rate in this replication is amazingly low; not even one base pair in a million matches out of sequence. However, when even one base pair is added to a new strain of DNA in an order differently than in the parent chain, it can be the basis of a mutation. These changes in DNA sequences are the microscopic origin of changes in traits of all studied living things. Even the smallest difference in a strand of DNA can result in a change in traits that can cost the life of the organism. Mutations can produce proteins with a new or altered function. In humans, the example of Sickle cell anemia3 is commonly given as its origin is a difference of only one base pair in a section of DNA that encodes red blood cells. Individual sequences of DNA that encode for specific proteins are called genes and are the units of heredity. Each one has a set nucleotide4 , and together all of the genes (and some sequence of DNA that apparently do not code for any biologically important functions) together make up the entire chromosome5.
The third line of defense of the immune system is called?	the malignant response	the sudden response	the asymptomatic response	the immune response	Like the immune systems of other vertebrates, the human immune system is adaptive. If pathogens manage to get through the body’s first two lines of defense, the third line of defense takes over. The third line of defense is referred to as the immune response . This defense is specific to a particular pathogen, and it allows the immune system to “remember” the pathogen after the infection is over. If the pathogen tries to invade the body again, the immune response against that pathogen will be much faster and stronger.
What's it called when gases turn back into liquids?	evaporation	dehydration	diffusion	condensation	As water cools in the clouds, condensation occurs. Condensation is when gases turn back into liquids.
What is a molecule made up of two subunits?	acid	chloride	enzyme	dimer
The pulmonary artery carries deoxygenated blood into the lungs from this?	brain	legs	bladder	heart	External Respiration The pulmonary artery carries deoxygenated blood into the lungs from the heart, where it branches and eventually becomes the capillary network composed of pulmonary capillaries. These pulmonary capillaries create the respiratory membrane with the alveoli (Figure 22.22). As the blood is pumped through this capillary network, gas exchange occurs. Although a small amount of the oxygen is able to dissolve directly into plasma from the alveoli, most of the oxygen is picked up by erythrocytes (red blood cells) and binds to a protein called hemoglobin, a process described later in this chapter. Oxygenated hemoglobin is red, causing the overall appearance of bright red oxygenated blood, which returns to the heart through the pulmonary veins. Carbon dioxide is released in the opposite direction of oxygen, from the blood to the alveoli. Some of the carbon dioxide is returned on hemoglobin, but can also be dissolved in plasma or is present as a converted form, also explained in greater detail later in this chapter. External respiration occurs as a function of partial pressure differences in oxygen and carbon dioxide between the alveoli and the blood in the pulmonary capillaries.
All of the living things in an area and the nonliving environment together make up what?	taiga	biosphere	biome	ecosystem	An ecosystem consists of all the living things in a given area, together with the nonliving environment. The nonliving environment includes water, sunlight, and other physical factors.
What areas of the planet are most birds native to?	mountainous	desert	tundra	tropical	Birds live and breed in most terrestrial habitats on Earth. They can be found on all seven continents, from the Arctic to Antarctica. However, the majority of bird species are native to tropical areas of the planet.
What is the basis of enzyme classification?	their mass	their shape	their color	reactions they catalyze	Enzymes are classified by the types of reactions that they catalyze.
Scientists use the principles of what to make predictions, which they then test?	their faith	their teachers	their guesses	their hypothesis	The experiment is a cornerstone in the scientific approach to gaining deeper knowledge about the natural world. Scientists use the principles of their hypothesis to make predictions, and then test them to see if their predictions are to be confirmed or rejected.
How many membranes form the mitochondrion structure of a cell?	three	one	five	two	Two separate membranes form the mitochondrion. The inner membrane folds into cristae which divide the organelle into three compartments: the intermembrane space (between outer and inner membranes), cristae space (formed by infoldings of the inner membrane), and the matrix (within the inner membrane). The Krebs Cycle takes place within the matrix. The compartments are critical for the electron transport chain structure and function. Glycolysis occurs in the cytoplasm of the cell, with the products of glycolysis entering the mitochondria to continue cellular respiration.
Lava that enters the water is called what?	saltwater lava	lava flow	magma runoff	pillow lava	Pillow lava is created from lava that enters the water. The volcanic vent may be underwater. The lava may flow over land and enter the water ( Figure below ). Once in the water, the lava cools very quickly. The lava forms round rocks that resemble pillows. Pillow lava is particularly common along mid-ocean ridges.
What do we call plants that shed their leaves seasonally each year?	lush plants	perennials	annuals	deciduous plants	After leaves turn color in the fall, they may all fall off the plant for the winter. Plants that shed their leaves seasonally each year are called deciduous plants . Shedding leaves is a strategy for reducing water loss during seasons of extreme dryness. On the downside, the plant must grow new leaves in the spring, and that takes a lot of energy and matter. Some plants may “bank” energy over the winter by storing food. That way, they are ready to grow new leaves as soon as spring arrives.

The presence of what in leaf cells makes most leaves appear green?

carbonate

hydrogen

sodium

chlorophyll

30.4 | Leaves By the end of this section, you will be able to: • Identify the parts of a typical leaf • Describe the internal structure and function of a leaf • Compare and contrast simple leaves and compound leaves • List and describe examples of modified leaves Leaves are the main sites for photosynthesis: the process by which plants synthesize food. Most leaves are usually green, due to the presence of chlorophyll in the leaf cells. However, some leaves may have different colors, caused by other plant pigments that mask the green chlorophyll. The thickness, shape, and size of leaves are adapted to the environment. Each variation helps a plant species maximize its chances of survival in a particular habitat. Usually, the leaves of plants growing in tropical rainforests have larger surface areas than those of plants growing in deserts or very cold conditions, which are likely to have a smaller surface area to minimize water loss.

What is the name of the project concerning genetics that is one of the landmark scientific events of the last 50 years?

blue beam project

human organism project

manhattan project

human genome project

Beginning with Mendel's pea plants, genetics has become one of the most important fields of biology. Genetics discusses genetics, from Mendel's pea plants to current ethical issues associated with this field. The completion of The Human Genome Project is one of the landmark scientific events of the last 50 years. Human genetics affects many, if not every, field of medicine. Technologies associated with genetics are involved in developing products to make our lives better, but have raised a number of ethical, legal and social issues.

Wind is one method for dispersal of what, ensuring a new generation?

eggs

dust

clouds

seeds

Most ecosystems are disturbed too often to attain what final, stable status?

even community

undisrupted community

calm community

climax community

Most ecosystems are disturbed too often to attain a final, stable climax community.

What kind of diet is typical for raptors, such as hawks and owls?

herbivorous

fishes

carnivorous or herbivorous

carnivorous

Raptors such as hawks and owls are carnivores. They hunt and eat mammals and other birds. Vultures are scavengers . They eat the remains of dead animals, such as roadkill. Aquatic birds generally eat fish or water plants. Perching birds may eat insects, fruit, honey, or nectar. Many fruit-eating birds play a key role in seed dispersal, and some nectar-feeding birds are important pollinators .

The most basic division of land plants is between what type of plants?

succulents and conifers

perennial and annual

deciduous and evergreen

nonvascular and vascular

The scientific classification of modern land plants is under constant revision. Informally, land plants can be classified into the groups listed in Table below . The most basic division is between nonvascular and vascular plants. Vascular plants are further divided into those that reproduce without seeds and those that reproduce with seeds. Seed plants, in turn, are divided into those that produce seeds in cones and those that produce seeds in the ovaries of flowers. You can read more about each of these groups of plants in the next lesson.

What do vaccines produce to combat viral diseases?

hyperthyroidism

sterility

sensitivity

immunity

The study of viruses is known as virology and people who study viruses are known as virologists . Viruses infect and live inside the cells of living organisms. When viruses infect the cells of their host, they may cause disease. For example, viruses cause AIDS (Acquired immune deficiency syndrome), influenza (flu), chicken pox, and the common cold. Therapy is sometimes difficult for viral diseases. Antibiotics have no effect on viruses and only a few antiviral drugs are available for some diseases. One of the best ways to prevent viral diseases is with a vaccine , which produces immunity . But vaccines are available for only a few diseases.

Internal functions are coordinated and regulated so that the internal environment of a living thing is relatively constant, referred to as what?

homogenesis

stabilizer

hypothesis

homeostasis

Biology - The Life Science • Internal functions are coordinated and regulated so that the internal environment of a living thing is relatively constant, referred to as homeostasis10 . Living things are organized in the microscopic level from atoms up to cells11 . Atoms are arranged into molecules, then into macromolecules12 , which make up organelles13 , which work together to form cells. Beyond this, cells are organized in higher levels to form entire multicellular organisms. Cells together form tissues14 , which make up organs, which are part of organ systems, which work together to form an entire organism. Of course, beyond this, organisms form populations which make up parts of an ecosystem. All of the Earth's ecosystems together form the diverse environment that is the earth. Example:sub atoms, atoms, molecules, cells, tissues, organs, organ systems, organisms, population, community, eco systems.

What is a long, tube-shaped bundle of neurons, protected by the vertebrae?

a dendrite

a ganglion

an axon

the spinal cord

The spinal cord is a long, tube-shaped bundle of neurons, protected by the vertebrae. It runs from the brain stem to the lower back. The main job of the spinal cord is to carry nerve impulses back and forth between the body and brain. The spinal cord is like a two-way highway. Messages about the body, both inside and out, pass through the spinal cord to the brain. Messages from the brain pass in the other direction through the spinal cord to tell the body what to do.

What does the kelvin scale measure?

precipitation

height

oxygen

temperature

The SI scale for measuring temperature is the Kelvin scale . However, some scientists use the Celsius scale instead. If you live in the U. S. , you are probably more familiar with the Fahrenheit scale. Table below compares all three temperature scales. What is the difference between the boiling and freezing points of water on each of these scales?.

Ash that enters the air naturally as a result of a volcano eruption is classified as what kind of pollutant?

natural pollutant

thick pollutant

secondary pollutant

primary pollutant

Primary pollutants enter the air directly. Some are released by natural processes, like ash from volcanoes. Most are released by human activities. They pour into the air from vehicles and smokestacks. Several of these pollutants are described below.

What happens when an increase in temperature of a gas in a rigid container happens?

container shrinks

gas explodes

pressure decreases

pressure increases

An increase in temperature of a gas in a rigid container increases the pressure.

Which reaction between alkyl halides and ammonia makes alkylamines?

nucleophobic reactions

nitrogen catabolism

conductive substitution reactions

nucleophilic substitution reactions

molecular masses. Primary amines tend to have boiling points intermediate between those of the corresponding alcohol and alkane. Moreover, secondary and tertiary amines have lower boiling points than primary amines of comparable molecular mass. Tertiary amines form cations analogous to the ammonium ion (NH 4+), in which all four H atoms are replaced by alkyl groups. Such substances, calledquaternary ammonium salts, can be chiral if all four substituents are different. (Amines with three different substituents are also chiral because the lone pair of electrons represents a fourth substituent. ) Alkylamines can be prepared by nucleophilic substitution reactions of alkyl halides with ammonia or other amines: Equation 24.12.

Genes are organized to make the control of gene expression easier. the promoter region is immediately upstream of this?

signalling sequence

propagate sequence

organic sequence

coding sequence

The Promoter and the Transcription Machinery Genes are organized to make the control of gene expression easier. The promoter region is immediately upstream of the coding sequence. This region can be short (only a few nucleotides in length) or quite long (hundreds of nucleotides long). The longer the promoter, the more available space for proteins to bind. This also adds more control to the transcription process. The length of the promoter is gene-specific and can differ dramatically between genes. Consequently, the level of control of gene expression can also differ quite dramatically between genes. The purpose of the promoter is to bind transcription factors that control the initiation of transcription. Within the promoter region, just upstream of the transcriptional start site, resides the TATA box. This box is simply a repeat of thymine and adenine dinucleotides (literally, TATA repeats). RNA polymerase binds to the transcription initiation complex, allowing transcription to occur. To initiate transcription, a transcription factor (TFIID) is the first to bind to the TATA box. Binding of TFIID recruits other transcription factors, including TFIIB, TFIIE, TFIIF, and TFIIH to the TATA box. Once this complex is assembled, RNA polymerase can bind to its upstream sequence. When bound along with the transcription factors, RNA polymerase is phosphorylated. This releases part of the protein from the DNA to activate the transcription initiation complex and places RNA polymerase in the correct orientation to begin transcription; DNA-bending protein brings the enhancer, which can be quite a distance from the gene, in contact with transcription factors and mediator proteins (Figure 16.9).

Which phylum is made up of segmented worms such as earthworms?

nematoda

chordata

arthropod

annelida

The phylum Annelida is made up of segmented worms such as earthworms. Segmented worms are divided into many repeating segments. There are roughly 15,000 species of annelids. Most belong to one of three classes. A species in each class is pictured in Figure below .

What is the transfer of thermal energy between substances called?

Radiation

Permeation

Diffusion

heat

Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature.

What functional units of chromosomes determine specific characteristics by coding for specific proteins?

cells

chromosomes

DNA

genes

Matched pairs of chromosomes in a diploid organism are called homologous (“same knowledge”) chromosomes. Homologous chromosomes are the same length and have specific nucleotide segments called genes in exactly the same location, or locus. Genes, the functional units of chromosomes, determine specific characteristics by coding for specific proteins. Traits are the variations of those characteristics. For example, hair color is a characteristic with traits that are blonde, brown, or black. Each copy of a homologous pair of chromosomes originates from a different parent; therefore, the genes themselves are not identical. The variation of individuals within a species is due to the specific combination of the genes inherited from both parents. Even a slightly altered sequence of nucleotides within a gene can result in an alternative trait. For example, there are three possible gene sequences on the human chromosome that code for blood type: sequence A, sequence B, and sequence O. Because all diploid human cells have two copies of the chromosome that determines blood type, the blood type (the trait) is determined by which two versions of the marker gene are inherited. It is possible to have two copies of the same gene sequence on both homologous chromosomes, with one on each (for example, AA, BB, or OO), or two different sequences, such as AB. Minor variations of traits, such as blood type, eye color, and handedness, contribute to the natural variation found within a species. However, if the entire DNA sequence from any pair of human homologous chromosomes is compared, the difference is less than one percent. The sex chromosomes, X and Y, are the single exception to the rule of homologous chromosome uniformity: Other than a small amount of homology that is necessary to accurately produce gametes, the genes found on the X and Y chromosomes are different.

Aside from light, incandescent light bulbs also give off what that wastes energy?

electricity

temperature

humidity

heat

The classroom in Figure above has artificial light sources in addition to natural sunlight. There are fluorescent lights on the ceiling of the room. There are also projectors on the ceiling that are shining light on screens. In these and most other artificial light sources, electricity provides the energy and some type of light bulb converts the electrical energy to visible light. How a light bulb produces visible light varies by type of bulb, as you can see in Table below . Incandescent light bulbs, which produce light by incandescence, give off a lot of heat as well as light, so they waste energy. Other light bulbs produce light by luminescence, so they produce little if any heat. These light bulbs use energy more efficiently. Which types of light bulbs do you use?.

What is an alpha particle with two protons and two neutrons called?

hydrogen nucleus

chloride nucleus

hydrogen nucleus

helium nucleus

In alpha decay, energy and an alpha particle are emitted by a nucleus that is unstable because it has too many protons. An alpha particle consists of two protons and two neutrons, so it is actually a helium nucleus.

Just as the reaction of a diol and a diacid forms a polyester, the reaction of a diacid and a diamine yields this?

acetone

phenol

polyethylene

polyamide

Polyamides Just as the reaction of a diol and a diacid forms a polyester (Section 15.8 "Preparation of Esters"), the reaction of a diacid and a diamine yields a polyamide. The two difunctional monomers often employed are adipic acid and 1,6-hexanediamine. The monomers condense by splitting out water to form a new product, which is still difunctional and thus can react further to yield a polyamide polymer.

Structural rearrangements of what include partial duplications, deletions, inversions, and translocations; duplications and deletions often produce offspring that survive but exhibit physical and mental abnormalities?

cells

neutrons

phenotypes

chromosomes

Chromosome Structural Rearrangements Cytologists have characterized numerous structural rearrangements in chromosomes, including partial duplications, deletions, inversions, and translocations. Duplications and deletions often produce offspring that survive but exhibit physical and mental abnormalities. Cri-du-chat (from the French for “cry of the cat”) is a syndrome associated with nervous system abnormalities and identifiable physical features that results from a deletion of most of the small arm of chromosome 5 (Figure 7.11). Infants with this genotype emit a characteristic high-pitched cry upon which the disorder’s name is based.

The e. coli chromosome, like many other bacterial chromosomes, is what shape?

triangular

oval

square

circular

What is the force of attraction between two masses?

momentum

electricity

inertia

gravity

Gravity is traditionally defined as a force of attraction between two masses. Weight measures the force of gravity and is expressed in newtons (N).

Chordates include vertebrates and invertebrates that have what?

a phloem

chordate

a endoderm

a notochord

Chordates include vertebrates and invertebrates that have a notochord.

Nearly how many millions of people die yearly due to air pollution?

eight million

two million

fifty million

five million

Almost 5 million people die each year because of air pollution. In fact, polluted air causes more deaths than traffic accidents. Air pollution harms the respiratory and circulatory systems. Both outdoor and indoor air can be polluted.

What instrument is used to record the length and strength of an earthquake?

microscope

transmitter

epicenter

seismograph

Earthquakes may take place every day near a volcano. But before an eruption the number and size of earthquakes increases. This is the result of magma pushing upward into the magma chamber. This motion causes stresses on neighboring rock to build up. Eventually the ground shakes. A continuous string of earthquakes may indicate that a volcano is about to erupt. Scientists use seismographs to record the length and strength of each earthquake.

Skeletal muscles must work in pairs to move bones back and forth at a joint because they can only do what?

expand

vibrate

pull

contract

Muscles can only contract. They can’t actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure below . When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm.

What type of molecules are secreted by the cell in local signaling?

sleeping molecules

word molecules

negaitive molecules

messenger molecules

Pulmonary ventilation in mammals occurs via what?

ingestion

inflammation

osmosis

inhalation

Mammalian Systems In mammals, pulmonary ventilation occurs via inhalation (breathing). During inhalation, air enters the body through the nasal cavity located just inside the nose (Figure 39.7). As air passes through the nasal cavity, the air is warmed to body temperature and humidified. The respiratory tract is coated with mucus to seal the tissues from direct contact with air. Mucus is high in water. As air crosses these surfaces of the mucous membranes, it picks up water. These processes help equilibrate the air to the body conditions, reducing any damage that cold, dry air can cause. Particulate matter that is floating in the air is removed in the nasal passages via mucus and cilia. The processes of warming, humidifying, and removing particles are important protective mechanisms that prevent damage to the trachea and lungs. Thus, inhalation serves several purposes in addition to bringing oxygen into the respiratory system.

Chemical signals are received by the target cell on what?

parent proteins

acidic proteins

inceptor proteins

receptor proteins

The target cell then needs to be able to recognize the signal. Chemical signals are received by the target cell on receptor proteins. Most receptor proteins are found associated with the plasma membrane, but some are also found inside the cell. Receptor proteins are very specific for only one particular signal molecule, much like a lock that recognizes only one key. Therefore, a cell has lots of receptor proteins to recognize the large number of cell signal molecules. There are three stages to sending and receiving a cell "message:" reception, transduction, and response.

What kind of organisms are prokaryotes?

multicellular organisms

viral

single - flagellated

single-celled

All prokaryotes are single-celled organisms.

What act like filters and remove pathogens from lymph?

electric nodes

spine nodes

tissue nodes

lymph nodes

Before lymph reaches the bloodstream, it passes through small oval structures called lymph nodes, which are located along the lymph vessels. Figure below shows where some of the body’s many lymph nodes are concentrated. Lymph nodes act like filters and remove pathogens from lymph.

What are the primary cells of adaptive immune response?

white blood cells

erythrocytes

red blood cells

lymphocytes

Lymphocytes: B Cells, T Cells, Plasma Cells, and Natural Killer Cells As stated above, lymphocytes are the primary cells of adaptive immune responses (Table 21.1). The two basic types of lymphocytes, B cells and T cells, are identical morphologically with a large central nucleus surrounded by a thin layer of cytoplasm. They are distinguished from each other by their surface protein markers as well as by the molecules they secrete. While B cells mature in red bone marrow and T cells mature in the thymus, they both initially develop from bone marrow. T cells migrate from bone marrow to the thymus gland where they further mature. B cells and T cells are found in many parts of the body, circulating in the bloodstream and lymph, and residing in secondary lymphoid organs, including the spleen and lymph nodes, which will be described later in this section. The human body contains approximately 10 12 lymphocytes.

What term refers to the friction of fluid, within itself and its surroundings?

salinity

elasticity

volume

viscosity

12.4 Viscosity and Laminar Flow; Poiseuille’s Law Laminar Flow and Viscosity When you pour yourself a glass of juice, the liquid flows freely and quickly. But when you pour syrup on your pancakes, that liquid flows slowly and sticks to the pitcher. The difference is fluid friction, both within the fluid itself and between the fluid and its surroundings. We call this property of fluids viscosity. Juice has low viscosity, whereas syrup has high viscosity. In the previous sections we have considered ideal fluids with little or no viscosity. In this section, we will investigate what factors, including viscosity, affect the rate of fluid flow. The precise definition of viscosity is based on laminar, or nonturbulent, flow. Before we can define viscosity, then, we need to define laminar flow and turbulent flow. Figure 12.10 shows both types of flow. Laminar flow is characterized by the smooth flow of the fluid in layers that do not mix. Turbulent flow, or turbulence, is characterized by eddies and swirls that mix layers of fluid together.

What do you call a unique substance formed when two or more elements combine chemically?

solution

component

mixture

compound

Compounds are unique substances that form when two or more elements combine chemically. The smallest particles of compounds are molecules. Some compounds form crystals instead.

Caves form over time when what causes rocks like limestone to dissolve?

air

weather

acid

water

It can be really exciting to explore a big underground cave like the one in this picture. Do you know how caves form? Believe it or not, water is the answer. Water slowly dissolves rocks, especially certain types of rocks such as limestone. How does something as mild and harmless as water cause hard rocks to dissolve? In this chapter, you’ll find out.

Cycloalkanes are hydrocarbons whose molecules are closed rings rather than straight or branched chains. a cyclic hydrocarbon is a hydrocarbon with a ring of these?

barium atoms

oxygen atoms

hydrogen atoms

carbon atoms

Cycloalkanes are hydrocarbons whose molecules are closed rings rather than straight or branched chains. A cyclic hydrocarbon is a hydrocarbon with a ring of carbon atoms.

Speciation, convergent evolution, and coevolution are types of what process?

microevolution

devolution

systemic evolution

macroevolution

Macroevolution occurs when microevolution takes place over a long period of time. Types of macroevolution include speciation, convergent evolution, and coevolution.

In what state do ionic compounds best conduct electricity?

plasma

gas

solid

liquid

Solid ionic compounds are poor conductors of electricity. The strong bonds between ions lock them into place in the crystal. However, in the liquid state, ionic compounds are good conductors of electricity. Most ionic compounds dissolve easily in water. When they dissolve, they separate into individual ions. The ions can move freely, so they are good conductors of electricity. Dissolved ionic compounds are called electrolytes.

What type of protein fibers in the cytoskeleton are the narrowest?

capillaries

macrophages

mitosis

microfilaments

Microfilaments Of the three types of protein fibers in the cytoskeleton, microfilaments are the narrowest. They function in cellular movement, have a diameter of about 7 nm, and are made of two intertwined strands of a globular protein called actin (Figure 4.23). For this reason, microfilaments are also known as actin filaments.

Which layer of the earth is molten?

the mantle

the inner core

the metallic core

the outer core

The dense, iron core forms the center of the Earth. Scientists know that the core is metal. The inner core is solid, and the outer core is molten. Here are some of the reasons they know this:.

What is the general name for a solid material that is formed via a natural process?

plasma

chemical

gas

mineral

A mineral is a solid material that forms by a natural process. A mineral can be made of an element or a compound. It has a specific chemical composition. Its chemical composition is different from other minerals. Each type of mineral has physical properties that differ from others. These properties include crystal structure, hardness, density, and color. For example, silver is a soft, shiny metal. Salt is a white, cube-shaped crystal. Diamond is an extremely hard, translucent crystal.

In a photosystem, pigments in the light-harvesting complex pass light energy to two special molecules of what in the reaction center?

nutrient

calcium

carbonate

chlorophyll

Figure 8.15 A photosystem consists of a light-harvesting complex and a reaction center. Pigments in the lightharvesting complex pass light energy to two special chlorophyll a molecules in the reaction center. The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor. The excited electron must then be replaced. In (a) photosystem II, the electron comes from the splitting of water, which releases oxygen as a waste product. In (b) photosystem I, the electron comes from the chloroplast electron transport chain discussed below.

What branch of science is the study of matter and energy?

negative science

unnatural science

natural science

physical science

Physical science is the study of matter and energy. That covers a lot of territory because matter refers to all the “stuff” that exists in the universe. It includes everything you can see and many things that you cannot see, including the air around you. Energy is also universal. It’s what gives matter the ability to move and change. Electricity, heat, and light are some of the forms that energy can take.

What make us sick when they become human parasites?

larvae

detritus

viruses

protozoa

Most protist diseases in humans are caused by animal-like protists, or protozoa. Protozoa make us sick when they become human parasites. Three examples of parasitic protozoa are described below.

The tendency of an object to resist a change in its motion is called?

friction

gravitation

magnetism

inertia

Inertia is the tendency of an object to resist a change in its motion. The inertia of an object depends on its mass. Objects with greater mass have greater inertia. To overcome inertia, an unbalanced force must be applied to an object.

Contributing to the blood-brain barrier is one of the jobs of glial cells, which support neurons in what system?

digestive system

peripheral nervous system

circulatory system

central nervous system

Glial Cells of the CNS One cell providing support to neurons of the CNS is the astrocyte, so named because it appears to be star-shaped under the microscope (astro- = “star”). Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). Those processes extend to interact with neurons, blood vessels, or the connective tissue covering the CNS that is called the pia mater (Figure 12.11). Generally, they are supporting cells for the neurons in the central nervous system. Some ways in which they support neurons in the central nervous system are by maintaining the concentration of chemicals in the extracellular space, removing excess signaling molecules, reacting to tissue damage, and contributing to the blood-brain barrier (BBB). The blood-brain barrier is a physiological barrier that keeps many.

During the condensation reaction of sugars what is removed, linking the two sugars?

air

hormones

chlorophyll

water

The simple sugars form the foundation of more complex carbohydrates. The cyclic forms of two sugars can be linked together by means of a condensation reaction. The figure below shows how a glucose molecule and a fructose molecule combine to form a sucrose molecule. A hydrogen atom from one molecule and a hydroxyl group from the other molecule are eliminated as water, with a resulting covalent bond linking the two sugars together at that point.

What develops into embryos inside seeds, from which the next sporophyte generation grows?

pupa

secretions

buds

zygotes

In seed plants, the gametophyte generation takes place in a cone or flower, which forms on the mature sporophyte plant. Each male gametophyte is just a few cells inside a grain of pollen. Each female gametophyte produces an egg inside an ovule. Pollination must occur for fertilization to take place. Zygotes develop into embryos inside seeds, from which the next sporophyte generation grows.

A change in temperature with distance is called a what?

solution gradient

oxygen gradient

speed gradient

temperature gradient

Air temperature changes with altitude. This does not occur in the same way as pressure and density, which decrease with altitude. Changes in air temperature are not regular. A change in temperature with distance is called a temperature gradient .

What sac, which was sitting on top of the flat embryo, envelops the embryo as it folds?

epithelial sac

uterus

umbilical sac

amniotic sac

The embryo, which begins as a flat sheet of cells, begins to acquire a cylindrical shape through the process of embryonic folding (Figure 28.14). The embryo folds laterally and again at either end, forming a C-shape with distinct head and tail ends. The embryo envelops a portion of the yolk sac, which protrudes with the umbilical cord from what will become the abdomen. The folding essentially creates a tube, called the primitive gut, that is lined by the endoderm. The amniotic sac, which was sitting on top of the flat embryo, envelops the embryo as it folds.

Catecholamines are a class of amine hormones synthesised form which amino acid?

phenylalanine

epinephrine

dopamine

tyrosine

Regulation of hormone production hormone levels are primarily controlled through negative feedback, in which rising levels of a hormone inhibit its?

Limited release

particular release

recent release

further release

37.4 Regulation of Hormone Production Hormone levels are primarily controlled through negative feedback, in which rising levels of a hormone inhibit its further release. The three mechanisms of hormonal release are humoral stimuli, hormonal stimuli, and neural stimuli. Humoral stimuli refers to the control of hormonal release in response to changes in extracellular fluid levels or ion levels. Hormonal stimuli refers to the release of hormones in response to hormones released by other endocrine glands. Neural stimuli refers to the release of hormones in response to neural stimulation.

Androgen secretion and sperm production are both controlled by hypothalamic and which other hormones?

adrenal

Testes

salivary

pituitary

The sum of the superscripts in an electron configuration is equal to the number of electrons in that atom, which is in turn equal to what number?

orbital number

metallic number

shell number

atomic number

Electron configuration notation eliminates the boxes and arrows of orbital filling diagrams. Each occupied sublevel designation is written followed by a superscript that is the number of electrons in that sublevel. For example, the hydrogen configuration is 1 s 1 , while the helium configuration is 1 s 2 . Multiple occupied sublevels are written one after another. The electron configuration of lithium is 1 s 2 2 s 1 . The sum of the superscripts in an electron configuration is equal to the number of electrons in that atom, which is in turn equal to its atomic number.

What part of the brain controls body position, coordination, and balance?

right brain

cerebrum

brain stem

cerebellum

The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeem’s cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance.

When light transfers its energy to objects, this is known as what?

condensation

accumulation

evaporation

absorption

Light may transfer its energy to matter rather than being reflected or transmitted by matter. This is called absorption . When light is absorbed, the added energy increases the temperature of matter. If you get into a car that has been sitting in the sun all day, the seats and other parts of the car’s interior may be almost too hot to touch, especially if they are black or very dark in color. That’s because dark colors absorb most of the sunlight that strikes them.

What do most amphibians breathe with as larvae?

nasal passages

pores

lungs

gills

Most amphibians breathe with gills as larvae and with lungs as adults. Additional oxygen is absorbed through the skin in most species. The skin is kept moist by mucus, which is secreted by mucous glands. In some species, mucous glands also produce toxins, which help protect the amphibians from predators. The golden frog shown in Figure below is an example of a toxic amphibian.

The chemical used by the ants to weed their garden turns out to be what kind?

sealant acid

sulfide acid

nitric acid

formic acid

A common age-related bone disease in which bone density and strength is decreased is know as what?

fibrosis

allergies

Stomach

osteoporosis

Osteoporosis is a common age-related bone disease in which bone density and strength is decreased. Watch this video (http://openstaxcollege. org/l/osteoporosis) to get a better understanding of how thoracic vertebrae may become weakened and may fracture due to this disease. How may vertebral osteoporosis contribute to kyphosis?.

Some fruit, like peaches, only have one big seed. what is this seed called?

the core

the middle

the seed

the pit

Dragonflies were one of the first insects to do what?

sexually reproduce

swim

fight

fly

Intestinal cells combine with proteins to create what?

lipoproteins

amino acids

chondrocytes

chylomicrons

Diffusion into intestinal cells, where they are combined with proteins to create chylomicrons.

Dutch elm trees used to be common, beautiful trees in the united states. now most of them have been killed by what?

cancer

carbon dioxide

beetles

dutch elm disease

Dutch elm trees used to be common, beautiful trees in the United States. Now most of them, like this tree, have been killed by Dutch elm disease. Dutch elm disease is caused by a fungus. This is just one example of how fungi can interact with other species.

Two major types of fungus-like protists are slime molds and which other?

black molds

foul molds

green molds

water molds

Fungus-like protists share many features with fungi. Like fungi, they are heterotrophs, meaning they must obtain food outside themselves. They also have cell walls and reproduce by forming spores, just like fungi. Fungus-like protists usually do not move, but a few develop movement at some point in their lives. Two major types of fungus-like protists are slime molds and water molds .

What are broken down during digestion to provide the amino acids needed for protein synthesis?

metabolytes

sugars

carbohydrates

dietary proteins

Dietary proteins are broken down during digestion to provide the amino acids needed for protein synthesis. Any extra proteins in the diet not needed for this purpose are used for energy or stored as fat. One gram of proteins provides 4 Calories of energy. Eating protein provides the amino acids for your cells to produce your own antibodies, muscle fibers and enzymes (as well as many other types of proteins).

A group of atoms that results when one hydrogen atom is removed from an alkane is referred to as what?

nitrate group

chloride group

hyrdrogen group

alkyl group

An alkyl group is a group of atoms that results when one hydrogen atom is removed from an alkane. The group is named by replacing the -ane suffix of the parent hydrocarbon with -yl. For example, the CH3 group derived from methane (CH4) results from subtracting one hydrogen atom and is called a methyl group. The alkyl groups we will use most frequently are listed in Table 12.4 "Common Alkyl Groups". Alkyl groups are not independent molecules; they are parts of molecules that we consider as a unit to name compounds systematically. Table 12.4 Common Alkyl Groups.

What is the term for stored energy that an object has due to its position or shape?

vertical energy

kinetic energy

mechanical energy

potential energy

A: Electric charges flow when they have electric potential energy. Potential energy is stored energy that an object has due to its position or shape.

What force is greater on rougher surfaces than smooth surfaces?

gravity

tension

acceleration

friction

Rougher surfaces have more friction between them than smoother surfaces. That’s why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. That’s why you can’t slide as far across ice with shoes as you can with skates (see Figure below ). The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction because they press together with greater force. Did you ever try to push boxes or furniture across the floor? It’s harder to overcome friction between heavier objects and the floor than it is between lighter objects and the floor.

Nitrogen is a very important element to living things, because it is part of nucleotides and amino acids that are the building blocks of nucleic acids and these?

follicles

cells

lipids

proteins

Cooperation between Bacteria and Eukaryotes: Nitrogen Fixation Nitrogen is a very important element to living things, because it is part of nucleotides and amino acids that are the building blocks of nucleic acids and proteins, respectively. Nitrogen is usually the most limiting element in terrestrial ecosystems, with atmospheric nitrogen, N2, providing the largest pool of available nitrogen. However, eukaryotes cannot use atmospheric, gaseous nitrogen to synthesize macromolecules. Fortunately, nitrogen can be “fixed,” meaning it is converted into ammonia (NH3) either biologically or abiotically. Abiotic nitrogen fixation occurs as a result of lightning or by industrial processes. Biological nitrogen fixation (BNF) is exclusively carried out by prokaryotes: soil bacteria, cyanobacteria, and Frankia spp. (filamentous bacteria interacting with actinorhizal plants such as alder, bayberry, and sweet fern). After photosynthesis, BNF is the second most important biological process on Earth. The equation representing the process is as follows.

In the mouth, enzymes present in what begin to chemically break down food?

lymph

blood

acid

saliva

The Human Digestive System The process of digestion begins in the mouth with the intake of food (Figure 16.4). The teeth play an important role in masticating (chewing) or physically breaking food into smaller particles. The enzymes present in saliva also begin to chemically break down food. The food is then swallowed and enters the esophagus—a long tube that connects the mouth to the stomach. Using peristalsis, or wave-like smooth-muscle contractions, the muscles of the esophagus push the food toward the stomach. The stomach contents are extremely acidic, with a pH between 1.5 and 2.5. This acidity kills microorganisms, breaks down food tissues, and activates digestive enzymes. Further breakdown of food takes place in the small intestine where bile produced by the liver, and enzymes produced by the small intestine and the pancreas, continue the process of digestion. The smaller molecules are absorbed into the blood stream through the epithelial cells lining the walls of the small intestine. The waste material travels on to the large intestine where water is absorbed and the drier waste material is compacted into feces; it is stored until it is excreted through the anus.

Unlike the cells of plants and fungi, animal cells lack what?

nuclei

mitochondria

flagella

cell wall

Like the cells of all eukaryotes, animal cells have a nucleus and other membrane-bound organelles (see Figure below ). Unlike the cells of plants and fungi, animal cells lack a cell wall. This gives animal cells flexibility. It lets them take on different shapes so they can become specialized to do particular jobs. The human nerve cell shown in Figure below is a good example. Its shape suits its function of transmitting nerve impulses over long distances. A nerve cell would be unable to take this shape if it were surrounded by a rigid cell wall.

Because alkali metals are so reactive, they are found in nature only in ________ with other elements?

competition

isolation

cooperation

combination

Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very “eager” to gain an electron. At the URL below, you can watch a video that shows just how reactive the alkali metals are.

What is the plane that divides the body or an organ vertically into right and left sides?

anatomical plane

median plane

parasagittal plane

sagittal plane

• The sagittal plane is the plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into unequal right and left sides, it is called a parasagittal plane or less commonly a longitudinal section. • The frontal plane is the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. The frontal plane is often referred to as a coronal plane. (“Corona” is Latin for “crown. ”) • The transverse plane is the plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.

What are the organs work together to allow us to see?

nose

lungs

heart

brain and eyes

The ability to see is called vision. The brain and eyes work together to allow us to see. The eyes collect and focus visible light and change it to electrical signals that travel to the brain. The brain interprets the signals and “tells” us what we are seeing.

The brain develops from this early tube structure and gives rise to specific regions of the adult brain. as the neural tube grows and differentiates, it enlarges into three vesicles that correspond to the forebrain, midbrain, and this?

astrobrain

anteriorbrain

rearbrain

hindbrain

into the brain, and the posterior region becomes the spinal cord. Tissues at the edges of the neural groove, when it closes off, are called the neural crest and migrate through the embryo to give rise to PNS structures as well as some non-nervous tissues. The brain develops from this early tube structure and gives rise to specific regions of the adult brain. As the neural tube grows and differentiates, it enlarges into three vesicles that correspond to the forebrain, midbrain, and hindbrain regions of the adult brain. Later in development, two of these three vesicles differentiate further, resulting in five vesicles. Those five vesicles can be aligned with the four major regions of the adult brain. The cerebrum is formed directly from the telencephalon. The diencephalon is the only region that keeps its embryonic name. The mesencephalon, metencephalon, and myelencephalon become the brain stem. The cerebellum also develops from the metencephalon and is a separate region of the adult brain. The spinal cord develops out of the rest of the neural tube and retains the tube structure, with the nervous tissue thickening and the hollow center becoming a very small central canal through the cord. The rest of the hollow center of the neural tube corresponds to open spaces within the brain called the ventricles, where cerebrospinal fluid is found.

Biotechnology uses what to solve problems?

geology

psycology

ecology

biology

Biotechnology is technology based on biological applications. These applications are increasingly used in medicine, agriculture and food science. Biotechnology combines many features of biology, including genetics, molecular biology, biochemistry, embryology, and cell biology. Many aspects of biotechnology center around DNA and its applications, otherwise known as DNA technology. We could devote a whole textbook to current applications of biotechnology, however, we will focus on the applications towards medicine and agriculture, and the extension into the forensic sciences. First, though, we need to understand DNA technology.

What are hurricanes called in the pacific?

twisters

tornados

rainstorms

typhoons

Tornadoes may also come from hurricanes. A hurricane ( Figure below ) is an enormous storm with high winds and heavy rains. Hurricanes may be hundreds of kilometers wide. They may travel for thousands of kilometers. The storm's wind speeds may be greater than 251 kilometers (156 miles) per hour. Hurricanes develop from tropical cyclones. Hurricanes are called typhoons in the Pacific.

What is the organ in which gas exchanges take place between blood and air?

kidney

heart

skin

lungs

Respiration begins with ventilation. This is the process of moving air in and out of the lungs. The lungs are the organs in which gas exchange takes place between blood and air.

What branch of science deals with the effects people have on the environment?

ecological science

physical science

cultural science

environmental science

Environmental science deals with the effects people have on the environment.

Sickle cell anemia is what type of disorder?

nongenetic disorder

autosomal dominant disorder

spontaneous mutation

autosomal recessive disorder

Sickle-Shaped and Normal Red Blood Cells. Sickle cell anemia is an autosomal recessive disorder. The mutation that causes the disorder affects just one amino acid in a single protein, but it has serious consequences for the affected person. This photo shows the sickle shape of red blood cells in people with sickle cell anemia.

Which region is just posterior to the mouth?

the diaphragm

the esophagus

the duodenum

the pharynx

What is the collective travel of sheep known as?

den

gaggle

load

herd

Like many other animals, sheep travel in herds. The tendency is for each individual sheep to stay with the herd. However, a sheep may sometimes wander off, depending on how strong the attraction is for a particular food or water supply. At other times, a sheep may become frightened and run off. Whether a sheep chooses to stay with the herd or go its own way depends on the balance between attraction to the herd and attraction to the outside influence.

What are these examples of: a person riding a carousel and a skydiver in free fall?

centripetal force

vibration

centrifugal force

acceleration

Examples of acceleration include a person riding a carousel and a skydiver in free fall.

Elements below the second period, such as silicon, do not form what as readily as second-period elements, and when they do form, they are weaker than those formed by second-period elements?

k. bonds

covalent bonds

magnetic bonds

n bonds

Silicon dioxide, silica, occurs in both crystalline and amorphous forms. The usual crystalline form of silicon dioxide is quartz, a hard, brittle, clear, colorless solid. It is useful in many ways—for architectural decorations, semiprecious jewels, and frequency control in radio transmitters. Silica takes many crystalline forms, or polymorphs, in nature. Trace amounts of Fe3+ in quartz give amethyst its characteristic purple color. The term quartz is also used for articles such as tubing and lenses that are manufactured from amorphous silica. Opal is a naturally occurring form of amorphous silica. The contrast in structure and physical properties between silicon dioxide and carbon dioxide is interesting, as illustrated in Figure 18.18. Solid carbon dioxide (dry ice) contains single CO2 molecules with each of the two oxygen atoms attached to the carbon atom by double bonds. Very weak intermolecular forces hold the molecules together in the crystal. The volatility of dry ice reflect these weak forces between molecules. In contrast, silicon dioxide is a covalent network solid. In silicon dioxide, each silicon atom links to four oxygen atoms by single bonds directed toward the corners of a regular tetrahedron, and SiO4 tetrahedra share oxygen atoms. This arrangement gives a three dimensional, continuous, silicon-oxygen network. A quartz crystal is a macromolecule of silicon dioxide. The difference between these two compounds is the ability of the group 14 elements to form strong π bonds. Secondperiod elements, such as carbon, form very strong π bonds, which is why carbon dioxide forms small molecules with strong double bonds. Elements below the second period, such as silicon, do not form π bonds as readily as secondperiod elements, and when they do form, the π bonds are weaker than those formed by second-period elements. For this reason, silicon dioxide does not contain π bonds but only σ bonds.

Through what method or methods of fertilization do amphibians sexually reproduce?

spawning or budding

asexual or sexual

mitosis and meiosis

external or internal

Amphibians reproduce sexually with either external or internal fertilization. They may attract mates with calls or scents. They do not produce amniotic eggs, so they must reproduce in water. Their larvae go through metamorphosis to change into the adult form.

The distance between corresponding points of adjacent waves is known as the __________

amplitude

absorption

bandwidth

wavelength

Wavelength is the distance between corresponding points of adjacent waves. Wavelengths of electromagnetic waves range from many kilometers to a tiny fraction of a millimeter.

Which system consists of all the nervous tissue that lies outside the central nervous system?

cerebral cortex

auxiliary nervous system

spinal cord

peripheral nervous system

The peripheral nervous system consists of all the nervous tissue that lies outside the central nervous system. It is connected to the central nervous system by nerves. It has several divisions and subdivisions that transmit nerve impulses between the central nervous system and the rest of the body.

What mechanism is used by living organisms to pass along genes?

chlorophyll

protein

digestion

dna

16 Gregor Mendel and biological inheritance Charles Darwin1 , for all he contributed to the science of biology, never knew about the mechanism by which living things inherit traits from previous generations, or how new traits arise. As any schoolchild can tell you, this mechanism of interitance has since been found to be DNA2 , or deoxyribonucleic acid. DNA allows for stable inheritance of traits: the code in each strand of DNA is replicated precisely through the pairing of basic units along each strand. The error rate in this replication is amazingly low; not even one base pair in a million matches out of sequence. However, when even one base pair is added to a new strain of DNA in an order differently than in the parent chain, it can be the basis of a mutation. These changes in DNA sequences are the microscopic origin of changes in traits of all studied living things. Even the smallest difference in a strand of DNA can result in a change in traits that can cost the life of the organism. Mutations can produce proteins with a new or altered function. In humans, the example of Sickle cell anemia3 is commonly given as its origin is a difference of only one base pair in a section of DNA that encodes red blood cells. Individual sequences of DNA that encode for specific proteins are called genes and are the units of heredity. Each one has a set nucleotide4 , and together all of the genes (and some sequence of DNA that apparently do not code for any biologically important functions) together make up the entire chromosome5.

The third line of defense of the immune system is called?

the malignant response

the sudden response

the asymptomatic response

the immune response

Like the immune systems of other vertebrates, the human immune system is adaptive. If pathogens manage to get through the body’s first two lines of defense, the third line of defense takes over. The third line of defense is referred to as the immune response . This defense is specific to a particular pathogen, and it allows the immune system to “remember” the pathogen after the infection is over. If the pathogen tries to invade the body again, the immune response against that pathogen will be much faster and stronger.

What's it called when gases turn back into liquids?

evaporation

dehydration

diffusion

condensation

As water cools in the clouds, condensation occurs. Condensation is when gases turn back into liquids.

What is a molecule made up of two subunits?

acid

chloride

enzyme

dimer

The pulmonary artery carries deoxygenated blood into the lungs from this?

brain

legs

bladder

heart

External Respiration The pulmonary artery carries deoxygenated blood into the lungs from the heart, where it branches and eventually becomes the capillary network composed of pulmonary capillaries. These pulmonary capillaries create the respiratory membrane with the alveoli (Figure 22.22). As the blood is pumped through this capillary network, gas exchange occurs. Although a small amount of the oxygen is able to dissolve directly into plasma from the alveoli, most of the oxygen is picked up by erythrocytes (red blood cells) and binds to a protein called hemoglobin, a process described later in this chapter. Oxygenated hemoglobin is red, causing the overall appearance of bright red oxygenated blood, which returns to the heart through the pulmonary veins. Carbon dioxide is released in the opposite direction of oxygen, from the blood to the alveoli. Some of the carbon dioxide is returned on hemoglobin, but can also be dissolved in plasma or is present as a converted form, also explained in greater detail later in this chapter. External respiration occurs as a function of partial pressure differences in oxygen and carbon dioxide between the alveoli and the blood in the pulmonary capillaries.

All of the living things in an area and the nonliving environment together make up what?

taiga

biosphere

biome

ecosystem

An ecosystem consists of all the living things in a given area, together with the nonliving environment. The nonliving environment includes water, sunlight, and other physical factors.

What areas of the planet are most birds native to?

mountainous

desert

tundra

tropical

Birds live and breed in most terrestrial habitats on Earth. They can be found on all seven continents, from the Arctic to Antarctica. However, the majority of bird species are native to tropical areas of the planet.

What is the basis of enzyme classification?

their mass

their shape

their color

reactions they catalyze

Enzymes are classified by the types of reactions that they catalyze.

Scientists use the principles of what to make predictions, which they then test?

their faith

their teachers

their guesses

their hypothesis

The experiment is a cornerstone in the scientific approach to gaining deeper knowledge about the natural world. Scientists use the principles of their hypothesis to make predictions, and then test them to see if their predictions are to be confirmed or rejected.

How many membranes form the mitochondrion structure of a cell?

three

one

five

two

Two separate membranes form the mitochondrion. The inner membrane folds into cristae which divide the organelle into three compartments: the intermembrane space (between outer and inner membranes), cristae space (formed by infoldings of the inner membrane), and the matrix (within the inner membrane). The Krebs Cycle takes place within the matrix. The compartments are critical for the electron transport chain structure and function. Glycolysis occurs in the cytoplasm of the cell, with the products of glycolysis entering the mitochondria to continue cellular respiration.

Lava that enters the water is called what?

saltwater lava

lava flow

magma runoff

pillow lava

Pillow lava is created from lava that enters the water. The volcanic vent may be underwater. The lava may flow over land and enter the water ( Figure below ). Once in the water, the lava cools very quickly. The lava forms round rocks that resemble pillows. Pillow lava is particularly common along mid-ocean ridges.

What do we call plants that shed their leaves seasonally each year?

lush plants

perennials

annuals

deciduous plants

After leaves turn color in the fall, they may all fall off the plant for the winter. Plants that shed their leaves seasonally each year are called deciduous plants . Shedding leaves is a strategy for reducing water loss during seasons of extreme dryness. On the downside, the plant must grow new leaves in the spring, and that takes a lot of energy and matter. Some plants may “bank” energy over the winter by storing food. That way, they are ready to grow new leaves as soon as spring arrives.