allenai/sciq · Datasets at Hugging Face

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Light waves differ based on their frequency and what else?	voltage	density	weight	amplitude	36.5 Vision Vision is the only photo responsive sense. Visible light travels in waves and is a very small slice of the electromagnetic radiation spectrum. Light waves differ based on their frequency (wavelength = hue) and amplitude (intensity = brightness). In the vertebrate retina, there are two types of light receptors (photoreceptors): cones and rods. Cones, which are the source of color vision, exist in three forms—L, M, and S—and they are differentially sensitive to different wavelengths. Cones are located in the retina, along with the dim-light, achromatic receptors (rods). Cones are found in the fovea, the central region of the retina, whereas rods are found in the peripheral regions of the retina. Visual signals travel from the eye over the axons of retinal ganglion cells, which make up the optic nerves. Ganglion cells come in several versions. Some ganglion cell axons carry information on form, movement, depth, and brightness, while other axons carry information on color and fine detail. Visual information is sent to the superior colliculi in the midbrain, where coordination of eye movements and integration of auditory information takes place. Visual information is also sent to the suprachiasmatic nucleus (SCN) of the hypothalamus, which plays a role in the circadian cycle.
What kind of diseases can be difficult to treat because they live inside the host's cells, making it hard to destroy them without killing host cells?	cancerous diseases	superfluous diseases	nucleus diseases	viral diseases	Viral diseases can be difficult to treat. They live inside the cells of their host, so it is hard to destroy them without killing host cells. Antibiotics also have no effect on viruses. Antiviral drugs are available, but only for a limited number of viruses.
What type of cellular respiration occurs in the presence of oxygen?	extracellular	hyperbaric	anaerobic	aerobic	There are two types of cellular respiration (see Cellular Respiration concept): aerobic and anaerobic. One occurs in the presence of oxygen ( aerobic ), and one occurs in the absence of oxygen ( anaerobic ). Both begin with glycolysis - the splitting of glucose.
Stomata must control the transpiration of water vapor and the exchange of carbon dioxide and oxygen that take place during what process?	fertilization	glycolysis	spermatogenesis	photosynthesis	For photosynthesis, stomata must control the transpiration of water vapor and the exchange of carbon dioxide and oxygen. Stomata are flanked by guard cells that swell or shrink by taking in or losing water through osmosis. When they do, they open or close the stomata.
If pollination and fertilization occur, a diploid zygote forms within an ovule, located where	testicle	bladder	uterus	ovary	If pollination and fertilization occur, a diploid zygote forms within an ovule in the ovary. The zygote develops into an embryo inside a seed, which forms from the ovule and also contains food to nourish the embryo. The ovary surrounding the seed may develop into a fruit. Fruits attract animals that may disperse the seeds they contain. If a seed germinates, it may grow into a mature sporophyte plant and repeat the cycle.
What makes up 99 percent of air?	dioxide and nitrogen	oxygen and dioxide	phosphorus and oxygen	nitrogen and oxygen	Figure below shows the main gases in air. Nitrogen and oxygen make up 99 percent of air. Argon and carbon dioxide make up much of the rest. These percentages are the same just about everywhere in the atmosphere.
What is the process in which producers get their energy from sources other than the sun?	biosynthesis	electrolysis	phototropism	chemosynthesis	There are also bacteria that use chemical processes to produce food. They get their energy from sources other than the sun, but they are still called producers. This process is known as chemosynthesis , and is common in ecosystems without sunlight, such as certain marine ecosystems.
Parasitism, mutualism, and commensalism are instances of what type of interaction?	antibiotic	semantic	enzymatic	symbiotic
The cell wall of plants is made up of a complex carbohydrate that is a polymer of what sugar?	fructose	sucrose	insulin	glucose	complex carbohydrate that is a polymer of glucose and that makes up the cell wall of plants.
Which metal is not a solid even at room temperature?	aluminum	iron	copper	mercury	A metal is an element that is a good conductor of heat and electricity. Metals are also malleable, which means that they can be hammered into very thin sheets without breaking, and ductile, which means that they can be drawn into wires. When a fresh surface of any metal is exposed, it will be very shiny, because it reflects light well. This property is referred to as luster. All metals are solid at room temperature except mercury (Hg), which is a liquid. The melting points of different metals vary widely. Mercury has the lowest melting point of all pure metals (−39°C), and tungsten (W) has the highest (3422°C). On the periodic table in Figure above , the metals are shaded blue and are located to the left of the bold stair-step line. About 80 percent of the elements are metals (see examples in Figure below ).
How do molecules react when a gas is heated?	they explode	they move slower	they disintegrate	they move faster	Gases are compressible, meaning that when put under high pressure, the particles are forced closer to one another. This decreases the amount of empty space and reduces the volume of the gas. Gas volume is also affected by temperature. When a gas is heated, its molecules move faster and the gas expands. Because of the variation in gas volume due to pressure and temperature changes, the comparison of gas volumes must be done at one standard temperature and pressure. Standard temperature and pressure (STP) is defined as 0°C (273.15 K) and 1 atm pressure. The molar volume of a gas is the volume of one mole of a gas at STP. At STP, one mole (6.02 × 10 23 representative particles) of any gas occupies a volume of 22.4 L ( Figure below ).
Mountain building and earthquakes are some of the responses of rocks when subected to what?	weather	time	erosion	stress	When plates are pushed or pulled, the rock is subjected to stress. Stress can cause a rock to change shape or to break. When a rock bends without breaking, it folds. When the rock breaks, it fractures. Mountain building and earthquakes are some of the responses rocks have to stress.
What is defined as maintaining a stable internal environment?	consciousness	peristalsis	ketosis	homeostasis	Lenses are made of transparent material such as glass or plastic with an index of refraction greater than that of air. At least one of the faces is a part of a sphere; a convex lens is thicker at the center than the edges, and a concave lens is thicker at the edges than the center. Convex lenses are called converging lenses, because they refract parallel light rays so that they meet. They are one of the most useful and important parts of all optical devices, and are found in eyeglasses, telescopes, microscopes, magnifying glasses, cameras and many other objects.
What element chemically weathers rock by combining with a metal?	hydrogen	nitrogen	carbon	oxygen	Oxygen chemically weathers rock by combining with a metal.
Porifera are parazoans that exhibit simple organization and lack true what?	cell membranes	molecules	nuclei	tissues	15.2 Sponges and Cnidarians Animals included in phylum Porifera are parazoans and do not possess true tissues. These organisms show a simple organization. Sponges have multiple cell types that are geared toward executing various metabolic functions. Cnidarians have outer and inner tissue layers sandwiching a noncellular mesoglea. Cnidarians possess a well-formed digestive system and carry out extracellular digestion. The cnidocyte is a specialized cell for delivering toxins to prey and predators. Cnidarians have separate sexes. They have a life cycle that involves morphologically distinct forms—medusoid and polypoid—at various stages in their life cycle.
The values of which factors are controlled by the experimenter over the course of an experiment?	independent approaches	other variables	independent elements	independent variables	A variable is a factor that can change over the course of an experiment. Independent variables are factors whose values are controlled by the experimenter to determine its relationship to an observed phenomenon (the dependent variable). Dependent variables change in response to the independent variable.
What are the most common causes of brain injuries?	alcohol poisoning	excessive shaking	lightning strikes	falls	Brain injuries can range from mild to extremely severe, but even mild injuries need medical attention. Brain injuries can result from falls, car accidents, violence, sports injuries, and war and combat. Falls are the most common cause of brain injuries, particularly in older adults and young children.
Electrons are located at fixed distances from the nucleus, what are they called?	energy concentrations	Energy layers	Positive levels	energy levels	Electrons are located at fixed distances from the nucleus, called energy levels. You can see the first three energy levels in the Figure below . The diagram also shows the maximum possible number of electrons at each energy level.
Which factor has a big impact on coastal climates?	tide	ocean waves	tsunami	large ocean currents	Large ocean currents can have a big impact on the climate of nearby coasts. The Gulf Stream, for example, carries warm water from near the equator up the eastern coast of North America. Look at the map in Figure below . It shows how the Gulf Stream warms both the water and land along the coast.
What occurs when light bends as it passes from one type of matter to another?	resonance	vibration	reflection	refraction	Light may be refracted by matter. The light is bent when it passes from one type of matter to another. Refraction of light is similar to refraction of sound waves. You can also read more about refraction of light in the lesson “Optics. ”.
What is a polymer formed by chain addition reactions between monomers that contain a double bond called?	an addition monolayer	a linear polymer	a branched polymer	an addition polymer	An addition polymer is a polymer formed by chain addition reactions between monomers that contain a double bond. Molecules of ethene can polymerize with each other under the right conditions to form the polymer called polyethylene.
What do you call resources that can be replaced at the rate they are being used?	innovative	viable	abundant	renewable	Renewable resources can be replaced at the rate they are being used.
The type of vesicle transport that moves a substance out of the cell is called?	endocytosis	morphogenesis	metabolism	exocytosis	Exocytosis is the type of vesicle transport that moves a substance out of the cell. A vesicle containing the substance moves through the cytoplasm to the cell membrane. Then, the vesicle membrane fuses with the cell membrane, and the substance is released outside the cell. You can watch an animation of exocytosis at the link below.
What characteristic of birds is related to the food they eat?	feet	feathers	tail	beak	The size and shape of the beak is related to the food the bird eats and can vary greatly among different birds. Parrots have down-curved, hooked bills, which are well-adapted for cracking seeds and nuts ( Figure below ). Hummingbirds, on the other hand, have long, thin, pointed bills, which are adapted for getting the nectar out of flowers ( Figure below ). Hawks, eagles, falcons and owls have a sharp, hooked beak.
What tube carries urine out of the body?	kidney	fallopian tube	uterus	urethra	The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body.
What plant products may be classified as simple, aggregate, multiple, or accessory, depending on their origin?	leaves	flowers	pods	fruits	Fruits may be classified as simple, aggregate, multiple, or accessory, depending on their origin (Figure 32.22). If the fruit develops from a single carpel or fused carpels of a single ovary, it is known as a simple fruit, as seen in nuts and beans. An aggregate fruit is one that develops from more than one carpel, but all are in the same flower: the mature carpels fuse together to form the entire fruit, as seen in the raspberry. Multiple fruit develops from an inflorescence or a cluster of flowers. An example is the pineapple, where the flowers fuse together to form the fruit. Accessory fruits (sometimes called false fruits) are not derived from the ovary, but from another part of the flower, such as the receptacle (strawberry) or the hypanthium (apples and pears).
What term describes the amount of material present in an object?	weight	density	volume	mass
What class of animals includes the subgroups rodents, carnivores, insectivores, bats, and primates?	amphibians	insects	reptiles	mammals	Subgroups of the mammals include rodents, carnivores, insectivores, bats, and primates.
What is the transfer of thermal energy by waves that can travel through empty space called?	vibration	convection	induction	radiation	Radiation is the transfer of thermal energy by waves that can travel through empty space. When the waves reach objects, they transfer thermal energy to the objects. This is how the sun’s energy reaches and warms Earth.
The lighter photic zone and darker aphotic zone are determined by what?	water density	water reflection	water shape	water depth	Two main zones based on depth of water are the photic zone and aphotic zone. The photic zone is the top 200 meters of water. The aphotic zone is water deeper than 200 meters. The deeper you go, the darker the water gets. That’s because sunlight cannot penetrate very far under water. Sunlight is needed for photosynthesis. So the depth of water determines whether photosynthesis is possible. There is enough sunlight for photosynthesis only in the photic zone.
Plant cuttings are an example of what type of reproduction?	autosexual	homosexual	heterosexual	asexual
Destructive interference in waves occurs when what things overlap?	three troughs	two waves	three waves	two troughs	Destructive interference in waves occurs when two troughs overlap.
When two plates of continental crust collide, the material pushes upward and forms what?	low mountain range	fault lines	valleys	high mountain range	When two plates of continental crust collide, the material pushes upward. This forms a high mountain range. The remnants of subducted oceanic crust remain beneath the continental convergence zone.
What is split to produce nuclear energy?	protons	molecules	chemicals	atoms	Nuclear energy is produced by splitting atoms. It also produces radioactive wastes that are very dangerous for many years.
What measures the amount of matter in an object?	weight	concentrations	amounts	mass	The inheritance of traits is not always as simple as Mendel's rules. Each characteristic Mendel investigated was controlled by one gene that had only two possible alleles, one of which was completely dominant over the other. We now know that inheritance is often more complicated than this. In blood types, for example, there are actually three alleles instead of two. And some traits even have more than three alleles.
What is the primary component of steel alloys?	alluminum	carbon	titanium	iron	Steels are a very important class of alloys. The many types of steels are primarily composed of iron, with various amounts of the elements carbon, chromium, manganese, nickel, molybdenum, and boron. Steels are widely used in building construction because of their strength, hardness, and resistance to corrosion. Most large modern structures like skyscrapers and stadiums are supported by a steel skeleton (see Figure below ).
Light energy is absorbed by which kind of molecule?	nutrient	inorganic	parasite	chlorophyll	Figure 5.12 Light energy is absorbed by a chlorophyll molecule and is passed along a pathway to other chlorophyll molecules. The energy culminates in a molecule of chlorophyll found in the reaction center. The energy “excites” one of its electrons enough to leave the molecule and be transferred to a nearby primary electron acceptor. A molecule of water splits to release an electron, which is needed to replace the one donated. Oxygen and hydrogen ions are also formed from the splitting of water.
What is the second class of fish after ray-finned fish?	star-finned fish	pine - finned fish	spar - finned fish	lobe-finned fish	There are about 27,000 species of bony fish ( Figure below ), which are divided into two classes: ray-finned fish and lobe-finned fish. Most bony fish are ray-finned. These thin fins consist of webs of skin over flexible spines. Lobe-finned fish, on the other hand, have fins that resemble stump-like appendages.
Regulation of endocrine depends on the hypothalmus and what other gland?	salivary	thyroid	adrenal	pituitary	45.3 The hypothalamus and pituitary are central to endocrine regulation.
What according to scientists is the major cause of depression?	high serotonin levels	low thyroid levels	high fat diets	low serotonin levels	Some people have low levels of the neurotransmitter called serotonin in their brain. Scientists think that this is one cause of depression. Medications called antidepressants help bring serotonin levels back to normal. For many people with depression, antidepressants control the symptoms of their depression and help them lead happy, productive lives.
What is a soft, malleable, and corrosion resistant material called?	gold	tin	copper	lead	Lead is a soft, malleable, and corrosion resistant material. The ancient Romans used lead to make water pipes, some of which are still in use today.
Momentum is a vector quantity that has the same direction as what?	inertia	object energy	initial speed	object ' s velocity	Momentum is a vector quantity that has the same direction as the velocity of the object.
What type of role does cartilage play in the human skeleton?	life saving	variable	important	insignificant
Prokaryotes divide via binary fission and do not undergo what process of cell division?	fusion	prophase	meiosis	mitosis	Reproduction Reproduction in prokaryotes is asexual and usually takes place by binary fission. Recall that the DNA of a prokaryote exists as a single, circular chromosome. Prokaryotes do not undergo mitosis. Rather the chromosome is replicated and the two resulting copies separate from one another, due to the growth of the cell. The prokaryote, now enlarged, is pinched inward at its equator and the two resulting cells, which are clones, separate. Binary fission does not provide an opportunity for genetic recombination or genetic diversity, but prokaryotes can share genes by three other mechanisms.
Light with the shortest wavelength appears as what color?	blue	red	green	violet	The wavelength of visible light determines the color that the light appears. Light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are the wavelengths of all the other colors of light.
What is lava called before it reaches the surface of the earth?	rock	crust	pyrite	magma	Minerals form as magma or lava cools.
What is the term for atherosclerosis of arteries that supply the heart muscle?	cardiovascular disease	rapid heart disease	essential heart disease	coronary heart disease	Atherosclerosis of arteries that supply the heart muscle is called coronary heart disease . This disease may or may not have symptoms, such as chest pain. As the disease progresses, there is an increased risk of heart attack. A heart attack occurs when the blood supply to part of the heart muscle is blocked and cardiac muscle fibers die. Coronary heart disease is the leading cause of death of adults in the United States.
Food is chemical energy stored in what?	DNA molecules	typical molecules	oxygen molecules	organic molecules	Food is chemical energy stored in organic molecules.
What has a bigger impact on water quality, natural events or human activity?	natural events	water quality	all of the above	human activity	Natural events, like storms, volcanic eruptions and earthquakes can cause major changes in water quality. But human-caused contaminants have a much greater impact on the quality of the water supply. Water is considered polluted either when it does not support a human use, like clean drinking water, or a use for other animals and plants. The overgrowth of algae, known as an algal bloom , can result from the runoff of fertilizer into bodies of water. This excess of nutrients allows the algae to grow beyond control, bring harm to the rest of the ecosystem.
What is the amount of energy required to begin a chemical reaction known as?	positive energy	decomposition energy	reaction energy	activation energy	All chemical reactions need energy to get started. Even reactions that release energy need a boost of energy in order to begin. The energy needed to start a chemical reaction is called activation energy . Activation energy is like the push a child needs to start going down a playground slide. The push gives the child enough energy to start moving, but once she starts, she keeps moving without being pushed again. Activation energy is illustrated in Figure below .
Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). it is most common along with the onset of puberty due to association with these?	thermal changes	mental changes	digestive changes	hormonal changes	Acne Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). It is most common along with the onset of puberty due to associated hormonal changes, but can also occur in infants and continue into adulthood. Hormones, such as androgens, stimulate the release of sebum. An overproduction and accumulation of sebum along with keratin can block hair follicles. This plug is initially white. The sebum, when oxidized by exposure to air, turns black. Acne results from infection by acne-causing bacteria (Propionibacterium and Staphylococcus), which can lead to redness and potential scarring due to the natural wound healing process (Figure 5.22).
What are the two main components in a battery?	anode and a vortex	filter and a cathode	vortex and a cathode	anode and a cathode	Zinc is an important component of many kinds of batteries. This metal is mined as zinc compounds, one of which is zinc carbonate. To obtain the pure metal, the ore must go through the following chemical processes:.
Lots of volcanoes form along which boundaries?	geyser plate boundaries	deposit plate bounderies	basalt plate boundaries	subduction plate boundaries	Lots of volcanoes form along subduction plate boundaries. The edges of the Pacific Plate are a long subduction boundary. Lines of volcanoes can form at subduction zones on oceanic or continental crust. Japan is an example of a volcanic arc on oceanic crust. The Cascade Range and Andes Mountains are volcanic arcs on continental crust.
Which body organ filters the blood in the body and creates urine?	the arteries	intestines	liver	the kidneys	The kidneys help the body maintain homeostasis in several ways. They filter all the blood in the body many times each day and produce urine. They control the amount of water and dissolved substances in the blood by excreting more or less of them in urine.
Compared with the molecules of many other substances, molecules of water are strongly attracted to what?	nothing	hydrogen	helium	each other	Compared with the molecules of many other substances, molecules of water are strongly attracted to each other. How is this likely to affect the boiling point of water?.
Greater reflection off what atmospheric layer allows am radio waves to travel even farther at night than they can during the day?	troposphere	stratosphere	exosphere	ionosphere	A: With greater reflection off the ionosphere, AM waves can travel even farther at night than they can during the day. Radio receivers can often pick up radio broadcasts at night from cities that are hundreds of miles away.
Earth spinning as air moves over its surface causes what?	axial tilt	seasons	centrifugal effect	coriolis effect	Earth is spinning as air moves over its surface. This causes the Coriolis effect. Winds blow on a diagonal over the surface due to Coriolis effect. From which direction do the northern trade winds blow?.
Beryllium hydride consists of a central beryllium atom with two single bonds to what?	calcium atoms	nitrogen atoms	metabolic atoms	hydrogen atoms	Beryllium hydride consists of a central beryllium atom with two single bonds to hydrogen atoms. Recall that it violates the octet rule.
Amides are actually formed by bringing together an amine-containing molecule and molecule containing what?	Fatty acid	oxidize acid	polymer acid	carboxylic acid	Amides are actually formed by bringing together an amine-containing molecule and a carboxylic acidcontaining molecule. A molecule of H2O is lost, much like when an ester forms:.
What are long living plasma cells called?	brain Cells	device cells	context cells	memory cells	Most plasma cells live for just a few days, but some of them live much longer. They may even survive for the lifetime of the individual. Long-living plasma cells are called memory cells. They retain a “memory” of a specific pathogen long after an infection is over. They help launch a rapid response against the pathogen if it invades the body again in the future.
When do homologous chromosomes separate and go to different gametes?	after meiosis	during electrolysis	before meiosis	during meiosis	During meiosis, homologous chromosomes separate and go to different gametes. Thus, the two alleles for each gene also go to different gametes. At the same time, different chromosomes assort independently. As a result, alleles for different genes assort independently as well. In these ways, alleles are shuffled and recombined in each parent’s gametes.
What type of cells are often the product of normal cells that have lost the ability to regulate the cell cycle?	sick cells	corrosive cells	uncontrolled cells	cancerous cells	Many cancerous cells are the products of normal cells that have lost the ability to regulate the cell cycle. The genes that encode the proteins involved in cell cycle regulation have mutations. One category of genes, called oncogenes, accelerate the cell cycle. Some cancers can be inherited, such as breast cancer (due to mutations in the BRCA1 and BRCA2 genes). Approximately five to ten percent of cancers are entirely hereditary. Other cancers are triggered by an environmental stimulus, such as through the relationship between tobacco smoke and lung cancer, or ultraviolet radiation and skin cancer.
Which ductless gland releases secretions directly into surrounding tissues and fluids?	adrenal glands	marrow gland	pineal gland	endocrine gland	Glandular Epithelium A gland is a structure made up of one or more cells modified to synthesize and secrete chemical substances. Most glands consist of groups of epithelial cells. A gland can be classified as an endocrine gland, a ductless gland that releases secretions directly into surrounding tissues and fluids (endo- = “inside”), or an exocrine gland whose secretions leave through a duct that opens directly, or indirectly, to the external environment (exo- = “outside”).
When different types of tissues work together to perform a unique function, what do they form?	produce	organs	Brian	organ	Plant Organ Systems In plants, just as in animals, similar cells working together form a tissue. When different types of tissues work together to perform a unique function, they form an organ; organs working together form organ systems. Vascular plants have two distinct organ systems: a shoot system, and a root system. The shoot system consists of two portions: the vegetative (nonreproductive) parts of the plant, such as the leaves and the stems, and the reproductive parts of the plant, which include flowers and fruits. The shoot system generally grows above ground, where it absorbs the light needed for photosynthesis. The root system, which supports the plants and absorbs water and minerals, is usually underground. Figure 30.2 shows the organ systems of a typical plant.
Over 90% of the energy we use comes originally from what?	horizon	earth	water	sun	Over 90% of the energy we use comes originally from the sun. Every day, the sun provides the earth with almost 10,000 times the amount of energy necessary to meet all of the world’s energy needs for that day. Our challenge is to find ways to convert and store incoming solar energy so that it can be used in reactions or chemical processes that are both convenient and nonpolluting. Plants and many bacteria capture solar energy through photosynthesis. We release the energy stored in plants when we burn wood or plant products such as ethanol. We also use this energy to fuel our bodies by eating food that comes directly from plants or from animals that got their energy by eating plants. Burning coal and petroleum also releases stored solar energy: These fuels are fossilized plant and animal matter. This chapter will introduce the basic ideas of an important area of science concerned with the amount of heat absorbed or released during chemical and physical changes—an area called thermochemistry. The concepts introduced in this chapter are widely used in almost all scientific and technical fields. Food scientists use them to determine the energy content of foods. Biologists study the energetics of living organisms, such as the metabolic combustion of sugar into carbon dioxide and water. The oil, gas, and transportation industries, renewable energy providers, and many others endeavor to find better methods to produce energy for our commercial and personal needs. Engineers strive to improve energy efficiency, find better ways to heat and cool our homes, refrigerate our food and drinks, and meet the energy and cooling needs of computers and electronics, among other applications. Understanding thermochemical.
What term is used to describe an illusion that light from faraway objects is reflected by a pool of water that is not really there?	Mirror	version	prototype	mirage	The most common type of mirage is an illusion that light from faraway objects is reflected by a pool of water that is not really there. Mirages are generally observed in deserts, when there is a hot layer of air near the ground. Given that the refractive index of air is lower for air at higher temperatures, explain how mirages can be formed.
How do prokaryotes reproduce?	unusually	inorganically	sexually	asexually
What does hemoglobin in blood carry to the cells?	nitrogen	methane	carbon dioxide	oxygen	Figure 39.19 The protein inside (a) red blood cells that carries oxygen to cells and carbon dioxide to the lungs is (b) hemoglobin. Hemoglobin is made up of four symmetrical subunits and four heme groups. Iron associated with the heme binds oxygen. It is the iron in hemoglobin that gives blood its red color.
Surface tension comes from the fact that particles at the surface of a liquid do not experience interactions from all directions which leads to what on the surface?	waves	degradation of forces	floating particles	imbalance of forces	Surface tension comes from the fact that particles at the surface of a liquid do not experience interactions from all directions, leading to an imbalance of forces on the surface. Surface tension is responsible for several well-known behaviors of liquids, including water. Liquids with high surface tension tend to bead up when present in small amounts ( - ball-ch10_s03_f06). Surface.
Where do biochemical reactions occer?	in the environment	outside organisms	inside labs	inside organisms	Biochemical reactions are chemical reactions that take place inside living things. Two of the most important biochemical reactions are photosynthesis and cellular respiration.
What type of behavior has the advantage of being flexible and capable of changing to suit changing conditions?	saved behavior	inherited behavior	noted behavior	learned behavior	Most animals are capable of learning, but animals that are more intelligent are better at learning and depend more on learned behaviors. The big advantage of learned behaviors over innate behaviors is that learned behaviors are flexible. They can be changed to suit changing conditions.
This process breaks rocks and other surface materials into much smaller pieces?	chemical reaction	corrosion	leaching	weathering
What is the main element in organic compounds?	nitrogen	hydrogen	oxygen	carbon	Carbon is the main element in organic compounds. Carbon can form stable bonds with many elements, including itself.
What is the basic unit of matter?	ions	neutrons	calories	atoms	The basic unit of matter is an atom . At the center of an atom is its nucleus . Protons are positively charged particles in the nucleus. Also in the nucleus are neutrons with no electrical charge. Orbiting the nucleus are tiny electrons. Electrons are negatively charged. An atom with the same number of protons and electrons is electrically neutral. If the atom has more or less electrons to protons it is called an ion . An ion will have positive charge if it has more protons than electrons. It will have negative charge if it has more electrons than protons.
What theory proposes that microorganisms are the cause of many diseases?	mutated theory	malignant theory	evolution theory	germ theory	The germ theory proposes that microorganisms are the cause of many diseases.
Water is a polar compound, so its molecules are attracted to each other and form what kind of bonds?	helium	mixed	carbon	hydrogen	Water is a polar compound, so its molecules are attracted to each other and form hydrogen bonds.
What is the term for a substance that causes the speed of a reaction to increase?	monite	indicate	component	catalyst	A catalyst is a substance that increases the speed of a reaction. Overall, a catalyst is not a reactant and is not used up, but it still affects how fast a reaction proceeds. However, a catalyst does not affect the extent or position of a reaction at equilibrium. It helps a reaction achieve equilibrium faster.
What is it called when rays focus at different distances from the lens?	angular aberration	constant aberration	carbon aberration	spherical aberration	Figure 26.30 Spherical aberration is caused by rays focusing at different distances from the lens.
Brass and bronze are examples of what type of mixture composed of two or more elements, at least one of which is a metal?	metalloid	halloid	compound	alloy	An alloy is a mixture composed of two or more elements, at least one of which is a metal. You are probably familiar with some alloys such as brass and bronze. Brass is an alloy of copper and zinc. Bronze is an alloy of copper and tin. Alloys are commonly used in manufactured items because the properties of these metal mixtures are often superior to a pure metal. Bronze is harder than copper and more easily cast. Brass is very malleable and its acoustic properties make it useful for musical instruments.
What is a region of repetitive noncoding nucleotide sequences at each end of a chromosome?	cytoskeleton	diploid	cellular	telomere	Reverse transcription also occurs with retrotransposons and during telomere synthesis in eukaryotes. Retrotransposons are self-replicating segments of eukaryotic genomes that use reverse transcriptase to move from one position in the genome to another via a RNA intermediate. A telomere is a region of repetitive noncoding nucleotide sequences at each end of a chromosome. These sequences protect the end of the chromosome from deterioration or from fusion with neighboring chromosomes. Each time DNA is replicated, small segments of DNA from the ends of the chromosome is lost. Telomerase is a reverse transcriptase that uses an RNA intermediate to elongate the 3' end of DNA strands in the telomere regions after each replication cycle.
What is the color of mercury oxide?	green	yellow	orange	red	Mercury(II) oxide is a red solid. When it is heated, it decomposes into mercury metal and oxygen gas.
At a convergent plate boundary, when one plate is oceanic, there are large what?	earthquakes	plateaus	lakes	volcanoes	At a convergent plate boundary, when one plate is oceanic, there are large volcanoes. These volcanoes are found in lines that outline the subduction zone. Earthquakes also happen in these zones. The Aleutian Islands that border southern Alaska are an island arc. In this winter image from space, the volcanoes are covered with snow.
What is the term for the wavelengths of light humans can see?	distinct light	radiation	ultraviolet light	visible light	Visible light is the wavelengths of light humans can see.
What is the charge on a single electron known as?	fundamental charge	basic charge	electron charge	elementary charge	The charge on a single electron is and is known as the elementary charge.
What mineral that occurs in bones helps combat osteoporosis?	potassium	magnesium	iron	calcium	Osteoporosis is a disease in which bones lose mass and become more fragile than they should be. Osteoporosis also makes bones more likely to break. Two of the easiest ways to prevent osteoporosis are eating a healthy diet that has the right amount of calcium and vitamin D and to do some sort of weight-bearing exercise every day. Foods that are a good source of calcium include milk, yogurt, and cheese. Non-dairy sources of calcium include Chinese cabbage, kale, and broccoli. Many fruit juices, fruit drinks, tofu, and cereals have calcium added to them. It is recommended that teenagers get 1300 mg of calcium every day. For example, one cup (8 fl. oz. ) of milk provides about 300 mg of calcium, or about 30% of the daily requirement. Other sources of calcium are pictured in the Figure below .
When the wind deposits sand, it forms small hills, what are these hills called?	mud puddles	sand tunnels	snow banks	sand dunes	When the wind deposits sand, it forms small hills. These hills are called sand dunes ( Figure below ). For sand dunes to form, there must be plenty of sand and wind. Sand dunes are found mainly in deserts and on beaches.
Carboxylic acids have an acidic hydrogen atom, but esters do not. what do esters have in place of an acidic hydrogen atom?	crystallization group	synthesis group	carbonation group	hydrocarbon group	Unlike ethers, esters have a carbonyl group. Unlike carboxylic acids, esters have no acidic hydrogen atom; they have a hydrocarbon group in its place.
Latitude, humidity, and elevation affect the type of what, a term for a large naturally occurring community?	climate	territory	ecosystem	biome	Factors affecting biome type include latitude, humidity, and elevation.
The distance between two crests of a wave of light is referred to as what, which is related to the color of light?	bandwidth	magnitude	spectrum	wavelength	wavelength : The distance between two crests of a wave of light. The color of light is related to its wavelength. This is inversely proportional to frequency.
What is the basic unit of structure and function in all organisms?	the electron	the atom	the neutron	the cell	The cell is the basic unit of structure and function of all organisms. The Cell Theory states that all living things are made of one or more cells, or the secretions of those cells, such as the organisms shown in Figure below . For example, shell and bone are built by cells from substances that they secrete into their surroundings. Cells come from cells that already exist, that is, they do not suddenly appear from nowhere. In organisms that are made of many cells (called multicellular organisms), every cell in the organism's body derives from the single cell that results from a fertilized egg. You will learn more about cells and the Cell Theory in Cells: The Cell Theory (Advanced) concept.
Which organ in the human body filters blood and excretes urine?	the thyroid	the liver	the bladder	the kidney	The kidneys filter all the blood in the body many times each day and produce a total of about 1.5 liters of urine . The kidneys control the amount of water, ions, and other substances in the blood by excreting more or less of them in urine. The kidneys also secrete hormones that help maintain homeostasis. Erythropoietin , for example, is a kidney hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete renin, which regulates blood pressure, and calcitriol, the active form of vitamin D, which helps maintain calcium for bones. The kidneys themselves are also regulated by hormones. For example, antidiuretic hormone from the hypothalamus stimulates the kidneys to produce more concentrated urine when the body is low on water.
Sugars are simple types of what biochemical compounds and possess relatively small molecules?	lipids	proteins	vegetables	carbohydrates	Carbohydrates are biochemical compounds that include sugar, starch, glycogen, and cellulose. Sugars are simple carbohydrates with relatively small molecules. Glucose is one of the smallest sugar molecules. Its chemical formula is C 6 H 12 O 6 . This means that a molecule of glucose contains 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose can obtain it by consuming plants or organisms that consume plants.
What type of tissue is blood?	nervous	muscular	epithelial	connective	Blood Blood is considered a connective tissue because it has a matrix, as shown in Figure 33.17. The living cell types are red blood cells (RBC), also called erythrocytes, and white blood cells (WBC), also called leukocytes. The fluid portion of whole blood, its matrix, is commonly called plasma.
What is the force that causes objects to fall down to the ground?	motion	velocity	pull	gravity	Regardless of what gravity is — a force between masses or the result of curves in space and time — the effects of gravity on motion are well known. You already know that gravity causes objects to fall down to the ground. Gravity affects the motion of objects in other ways as well.
The distance of stars is measured in what terms, meaning the light takes many thousands of years to reach us?	light hours	light months	light decades	light years	Viewing distant stars is looking back in time. The stars we see are many thousands of light years away, which means the light takes many thousands of years to reach us. Thus the stars we see in the sky are how they looked thousands of years ago.
What type of matter often sinks into cracks between rocks?	energy	algae	vapor	liquid
Name a one-celled organism that can be found on your skin, in the ground, or in all different types of water.	pathogens	virus	fungus	bacteria	Cells are found in all different types of environments, and these environments are constantly changing. For example, one-celled organisms, like bacteria, can be found on your skin, in the ground, or in all different types of water. Therefore, cells need a way to protect themselves. This job is done by the cell membrane, which is also known as the plasma membrane.
What type of power is generated using a nonrenewable resource?	water power	wind power	solar power	nuclear power	Chuck Szmurlo (Wikimedia: Cszmurlo). Nuclear power is generated using a nonrenewable resource . CC BY 2.5.
The earth is tilted on its what?	radius	top	compass	axis	The Earth is tilted on its axis ( Figure above ). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day ( Figure below ).
What can human facial expressions communicate?	theories	behaviors	ideas	emotions	Human facial expressions can communicate a range of emotions.

Light waves differ based on their frequency and what else?

voltage

density

weight

amplitude

36.5 Vision Vision is the only photo responsive sense. Visible light travels in waves and is a very small slice of the electromagnetic radiation spectrum. Light waves differ based on their frequency (wavelength = hue) and amplitude (intensity = brightness). In the vertebrate retina, there are two types of light receptors (photoreceptors): cones and rods. Cones, which are the source of color vision, exist in three forms—L, M, and S—and they are differentially sensitive to different wavelengths. Cones are located in the retina, along with the dim-light, achromatic receptors (rods). Cones are found in the fovea, the central region of the retina, whereas rods are found in the peripheral regions of the retina. Visual signals travel from the eye over the axons of retinal ganglion cells, which make up the optic nerves. Ganglion cells come in several versions. Some ganglion cell axons carry information on form, movement, depth, and brightness, while other axons carry information on color and fine detail. Visual information is sent to the superior colliculi in the midbrain, where coordination of eye movements and integration of auditory information takes place. Visual information is also sent to the suprachiasmatic nucleus (SCN) of the hypothalamus, which plays a role in the circadian cycle.

What kind of diseases can be difficult to treat because they live inside the host's cells, making it hard to destroy them without killing host cells?

cancerous diseases

superfluous diseases

nucleus diseases

viral diseases

Viral diseases can be difficult to treat. They live inside the cells of their host, so it is hard to destroy them without killing host cells. Antibiotics also have no effect on viruses. Antiviral drugs are available, but only for a limited number of viruses.

What type of cellular respiration occurs in the presence of oxygen?

extracellular

hyperbaric

anaerobic

aerobic

There are two types of cellular respiration (see Cellular Respiration concept): aerobic and anaerobic. One occurs in the presence of oxygen ( aerobic ), and one occurs in the absence of oxygen ( anaerobic ). Both begin with glycolysis - the splitting of glucose.

Stomata must control the transpiration of water vapor and the exchange of carbon dioxide and oxygen that take place during what process?

fertilization

glycolysis

spermatogenesis

photosynthesis

For photosynthesis, stomata must control the transpiration of water vapor and the exchange of carbon dioxide and oxygen. Stomata are flanked by guard cells that swell or shrink by taking in or losing water through osmosis. When they do, they open or close the stomata.

If pollination and fertilization occur, a diploid zygote forms within an ovule, located where

testicle

bladder

uterus

ovary

If pollination and fertilization occur, a diploid zygote forms within an ovule in the ovary. The zygote develops into an embryo inside a seed, which forms from the ovule and also contains food to nourish the embryo. The ovary surrounding the seed may develop into a fruit. Fruits attract animals that may disperse the seeds they contain. If a seed germinates, it may grow into a mature sporophyte plant and repeat the cycle.

What makes up 99 percent of air?

dioxide and nitrogen

oxygen and dioxide

phosphorus and oxygen

nitrogen and oxygen

Figure below shows the main gases in air. Nitrogen and oxygen make up 99 percent of air. Argon and carbon dioxide make up much of the rest. These percentages are the same just about everywhere in the atmosphere.

What is the process in which producers get their energy from sources other than the sun?

biosynthesis

electrolysis

phototropism

chemosynthesis

There are also bacteria that use chemical processes to produce food. They get their energy from sources other than the sun, but they are still called producers. This process is known as chemosynthesis , and is common in ecosystems without sunlight, such as certain marine ecosystems.

Parasitism, mutualism, and commensalism are instances of what type of interaction?

antibiotic

semantic

enzymatic

symbiotic

The cell wall of plants is made up of a complex carbohydrate that is a polymer of what sugar?

fructose

sucrose

insulin

glucose

complex carbohydrate that is a polymer of glucose and that makes up the cell wall of plants.

Which metal is not a solid even at room temperature?

aluminum

iron

copper

mercury

A metal is an element that is a good conductor of heat and electricity. Metals are also malleable, which means that they can be hammered into very thin sheets without breaking, and ductile, which means that they can be drawn into wires. When a fresh surface of any metal is exposed, it will be very shiny, because it reflects light well. This property is referred to as luster. All metals are solid at room temperature except mercury (Hg), which is a liquid. The melting points of different metals vary widely. Mercury has the lowest melting point of all pure metals (−39°C), and tungsten (W) has the highest (3422°C). On the periodic table in Figure above , the metals are shaded blue and are located to the left of the bold stair-step line. About 80 percent of the elements are metals (see examples in Figure below ).

How do molecules react when a gas is heated?

they explode

they move slower

they disintegrate

they move faster

Gases are compressible, meaning that when put under high pressure, the particles are forced closer to one another. This decreases the amount of empty space and reduces the volume of the gas. Gas volume is also affected by temperature. When a gas is heated, its molecules move faster and the gas expands. Because of the variation in gas volume due to pressure and temperature changes, the comparison of gas volumes must be done at one standard temperature and pressure. Standard temperature and pressure (STP) is defined as 0°C (273.15 K) and 1 atm pressure. The molar volume of a gas is the volume of one mole of a gas at STP. At STP, one mole (6.02 × 10 23 representative particles) of any gas occupies a volume of 22.4 L ( Figure below ).

Mountain building and earthquakes are some of the responses of rocks when subected to what?

weather

time

erosion

stress

When plates are pushed or pulled, the rock is subjected to stress. Stress can cause a rock to change shape or to break. When a rock bends without breaking, it folds. When the rock breaks, it fractures. Mountain building and earthquakes are some of the responses rocks have to stress.

What is defined as maintaining a stable internal environment?

consciousness

peristalsis

ketosis

homeostasis

Lenses are made of transparent material such as glass or plastic with an index of refraction greater than that of air. At least one of the faces is a part of a sphere; a convex lens is thicker at the center than the edges, and a concave lens is thicker at the edges than the center. Convex lenses are called converging lenses, because they refract parallel light rays so that they meet. They are one of the most useful and important parts of all optical devices, and are found in eyeglasses, telescopes, microscopes, magnifying glasses, cameras and many other objects.

What element chemically weathers rock by combining with a metal?

hydrogen

nitrogen

carbon

oxygen

Oxygen chemically weathers rock by combining with a metal.

Porifera are parazoans that exhibit simple organization and lack true what?

cell membranes

molecules

nuclei

tissues

15.2 Sponges and Cnidarians Animals included in phylum Porifera are parazoans and do not possess true tissues. These organisms show a simple organization. Sponges have multiple cell types that are geared toward executing various metabolic functions. Cnidarians have outer and inner tissue layers sandwiching a noncellular mesoglea. Cnidarians possess a well-formed digestive system and carry out extracellular digestion. The cnidocyte is a specialized cell for delivering toxins to prey and predators. Cnidarians have separate sexes. They have a life cycle that involves morphologically distinct forms—medusoid and polypoid—at various stages in their life cycle.

The values of which factors are controlled by the experimenter over the course of an experiment?

independent approaches

other variables

independent elements

independent variables

A variable is a factor that can change over the course of an experiment. Independent variables are factors whose values are controlled by the experimenter to determine its relationship to an observed phenomenon (the dependent variable). Dependent variables change in response to the independent variable.

What are the most common causes of brain injuries?

alcohol poisoning

excessive shaking

lightning strikes

falls

Brain injuries can range from mild to extremely severe, but even mild injuries need medical attention. Brain injuries can result from falls, car accidents, violence, sports injuries, and war and combat. Falls are the most common cause of brain injuries, particularly in older adults and young children.

Electrons are located at fixed distances from the nucleus, what are they called?

energy concentrations

Energy layers

Positive levels

energy levels

Electrons are located at fixed distances from the nucleus, called energy levels. You can see the first three energy levels in the Figure below . The diagram also shows the maximum possible number of electrons at each energy level.

Which factor has a big impact on coastal climates?

tide

ocean waves

tsunami

large ocean currents

Large ocean currents can have a big impact on the climate of nearby coasts. The Gulf Stream, for example, carries warm water from near the equator up the eastern coast of North America. Look at the map in Figure below . It shows how the Gulf Stream warms both the water and land along the coast.

What occurs when light bends as it passes from one type of matter to another?

resonance

vibration

reflection

refraction

Light may be refracted by matter. The light is bent when it passes from one type of matter to another. Refraction of light is similar to refraction of sound waves. You can also read more about refraction of light in the lesson “Optics. ”.

What is a polymer formed by chain addition reactions between monomers that contain a double bond called?

an addition monolayer

a linear polymer

a branched polymer

an addition polymer

An addition polymer is a polymer formed by chain addition reactions between monomers that contain a double bond. Molecules of ethene can polymerize with each other under the right conditions to form the polymer called polyethylene.

What do you call resources that can be replaced at the rate they are being used?

innovative

viable

abundant

renewable

Renewable resources can be replaced at the rate they are being used.

The type of vesicle transport that moves a substance out of the cell is called?

endocytosis

morphogenesis

metabolism

exocytosis

Exocytosis is the type of vesicle transport that moves a substance out of the cell. A vesicle containing the substance moves through the cytoplasm to the cell membrane. Then, the vesicle membrane fuses with the cell membrane, and the substance is released outside the cell. You can watch an animation of exocytosis at the link below.

What characteristic of birds is related to the food they eat?

feet

feathers

tail

beak

The size and shape of the beak is related to the food the bird eats and can vary greatly among different birds. Parrots have down-curved, hooked bills, which are well-adapted for cracking seeds and nuts ( Figure below ). Hummingbirds, on the other hand, have long, thin, pointed bills, which are adapted for getting the nectar out of flowers ( Figure below ). Hawks, eagles, falcons and owls have a sharp, hooked beak.

What tube carries urine out of the body?

kidney

fallopian tube

uterus

urethra

The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body.

What plant products may be classified as simple, aggregate, multiple, or accessory, depending on their origin?

leaves

flowers

pods

fruits

Fruits may be classified as simple, aggregate, multiple, or accessory, depending on their origin (Figure 32.22). If the fruit develops from a single carpel or fused carpels of a single ovary, it is known as a simple fruit, as seen in nuts and beans. An aggregate fruit is one that develops from more than one carpel, but all are in the same flower: the mature carpels fuse together to form the entire fruit, as seen in the raspberry. Multiple fruit develops from an inflorescence or a cluster of flowers. An example is the pineapple, where the flowers fuse together to form the fruit. Accessory fruits (sometimes called false fruits) are not derived from the ovary, but from another part of the flower, such as the receptacle (strawberry) or the hypanthium (apples and pears).

What term describes the amount of material present in an object?

weight

density

volume

mass

What class of animals includes the subgroups rodents, carnivores, insectivores, bats, and primates?

amphibians

insects

reptiles

mammals

Subgroups of the mammals include rodents, carnivores, insectivores, bats, and primates.

What is the transfer of thermal energy by waves that can travel through empty space called?

vibration

convection

induction

radiation

Radiation is the transfer of thermal energy by waves that can travel through empty space. When the waves reach objects, they transfer thermal energy to the objects. This is how the sun’s energy reaches and warms Earth.

The lighter photic zone and darker aphotic zone are determined by what?

water density

water reflection

water shape

water depth

Two main zones based on depth of water are the photic zone and aphotic zone. The photic zone is the top 200 meters of water. The aphotic zone is water deeper than 200 meters. The deeper you go, the darker the water gets. That’s because sunlight cannot penetrate very far under water. Sunlight is needed for photosynthesis. So the depth of water determines whether photosynthesis is possible. There is enough sunlight for photosynthesis only in the photic zone.

Plant cuttings are an example of what type of reproduction?

autosexual

homosexual

heterosexual

asexual

Destructive interference in waves occurs when what things overlap?

three troughs

two waves

three waves

two troughs

Destructive interference in waves occurs when two troughs overlap.

When two plates of continental crust collide, the material pushes upward and forms what?

low mountain range

fault lines

valleys

high mountain range

When two plates of continental crust collide, the material pushes upward. This forms a high mountain range. The remnants of subducted oceanic crust remain beneath the continental convergence zone.

What is split to produce nuclear energy?

protons

molecules

chemicals

atoms

Nuclear energy is produced by splitting atoms. It also produces radioactive wastes that are very dangerous for many years.

What measures the amount of matter in an object?

weight

concentrations

amounts

mass

The inheritance of traits is not always as simple as Mendel's rules. Each characteristic Mendel investigated was controlled by one gene that had only two possible alleles, one of which was completely dominant over the other. We now know that inheritance is often more complicated than this. In blood types, for example, there are actually three alleles instead of two. And some traits even have more than three alleles.

What is the primary component of steel alloys?

alluminum

carbon

titanium

iron

Steels are a very important class of alloys. The many types of steels are primarily composed of iron, with various amounts of the elements carbon, chromium, manganese, nickel, molybdenum, and boron. Steels are widely used in building construction because of their strength, hardness, and resistance to corrosion. Most large modern structures like skyscrapers and stadiums are supported by a steel skeleton (see Figure below ).

Light energy is absorbed by which kind of molecule?

nutrient

inorganic

parasite

chlorophyll

Figure 5.12 Light energy is absorbed by a chlorophyll molecule and is passed along a pathway to other chlorophyll molecules. The energy culminates in a molecule of chlorophyll found in the reaction center. The energy “excites” one of its electrons enough to leave the molecule and be transferred to a nearby primary electron acceptor. A molecule of water splits to release an electron, which is needed to replace the one donated. Oxygen and hydrogen ions are also formed from the splitting of water.

What is the second class of fish after ray-finned fish?

star-finned fish

pine - finned fish

spar - finned fish

lobe-finned fish

There are about 27,000 species of bony fish ( Figure below ), which are divided into two classes: ray-finned fish and lobe-finned fish. Most bony fish are ray-finned. These thin fins consist of webs of skin over flexible spines. Lobe-finned fish, on the other hand, have fins that resemble stump-like appendages.

Regulation of endocrine depends on the hypothalmus and what other gland?

salivary

thyroid

adrenal

pituitary

45.3 The hypothalamus and pituitary are central to endocrine regulation.

What according to scientists is the major cause of depression?

high serotonin levels

low thyroid levels

high fat diets

low serotonin levels

Some people have low levels of the neurotransmitter called serotonin in their brain. Scientists think that this is one cause of depression. Medications called antidepressants help bring serotonin levels back to normal. For many people with depression, antidepressants control the symptoms of their depression and help them lead happy, productive lives.

What is a soft, malleable, and corrosion resistant material called?

gold

tin

copper

lead

Lead is a soft, malleable, and corrosion resistant material. The ancient Romans used lead to make water pipes, some of which are still in use today.

Momentum is a vector quantity that has the same direction as what?

inertia

object energy

initial speed

object ' s velocity

Momentum is a vector quantity that has the same direction as the velocity of the object.

What type of role does cartilage play in the human skeleton?

life saving

variable

important

insignificant

Prokaryotes divide via binary fission and do not undergo what process of cell division?

fusion

prophase

meiosis

mitosis

Reproduction Reproduction in prokaryotes is asexual and usually takes place by binary fission. Recall that the DNA of a prokaryote exists as a single, circular chromosome. Prokaryotes do not undergo mitosis. Rather the chromosome is replicated and the two resulting copies separate from one another, due to the growth of the cell. The prokaryote, now enlarged, is pinched inward at its equator and the two resulting cells, which are clones, separate. Binary fission does not provide an opportunity for genetic recombination or genetic diversity, but prokaryotes can share genes by three other mechanisms.

Light with the shortest wavelength appears as what color?

blue

red

green

violet

The wavelength of visible light determines the color that the light appears. Light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are the wavelengths of all the other colors of light.

What is lava called before it reaches the surface of the earth?

rock

crust

pyrite

magma

Minerals form as magma or lava cools.

What is the term for atherosclerosis of arteries that supply the heart muscle?

cardiovascular disease

rapid heart disease

essential heart disease

coronary heart disease

Atherosclerosis of arteries that supply the heart muscle is called coronary heart disease . This disease may or may not have symptoms, such as chest pain. As the disease progresses, there is an increased risk of heart attack. A heart attack occurs when the blood supply to part of the heart muscle is blocked and cardiac muscle fibers die. Coronary heart disease is the leading cause of death of adults in the United States.

Food is chemical energy stored in what?

DNA molecules

typical molecules

oxygen molecules

organic molecules

Food is chemical energy stored in organic molecules.

What has a bigger impact on water quality, natural events or human activity?

natural events

water quality

all of the above

human activity

Natural events, like storms, volcanic eruptions and earthquakes can cause major changes in water quality. But human-caused contaminants have a much greater impact on the quality of the water supply. Water is considered polluted either when it does not support a human use, like clean drinking water, or a use for other animals and plants. The overgrowth of algae, known as an algal bloom , can result from the runoff of fertilizer into bodies of water. This excess of nutrients allows the algae to grow beyond control, bring harm to the rest of the ecosystem.

What is the amount of energy required to begin a chemical reaction known as?

positive energy

decomposition energy

reaction energy

activation energy

All chemical reactions need energy to get started. Even reactions that release energy need a boost of energy in order to begin. The energy needed to start a chemical reaction is called activation energy . Activation energy is like the push a child needs to start going down a playground slide. The push gives the child enough energy to start moving, but once she starts, she keeps moving without being pushed again. Activation energy is illustrated in Figure below .

Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). it is most common along with the onset of puberty due to association with these?

thermal changes

mental changes

digestive changes

hormonal changes

Acne Acne is a skin disturbance that typically occurs on areas of the skin that are rich in sebaceous glands (face and back). It is most common along with the onset of puberty due to associated hormonal changes, but can also occur in infants and continue into adulthood. Hormones, such as androgens, stimulate the release of sebum. An overproduction and accumulation of sebum along with keratin can block hair follicles. This plug is initially white. The sebum, when oxidized by exposure to air, turns black. Acne results from infection by acne-causing bacteria (Propionibacterium and Staphylococcus), which can lead to redness and potential scarring due to the natural wound healing process (Figure 5.22).

What are the two main components in a battery?

anode and a vortex

filter and a cathode

vortex and a cathode

anode and a cathode

Zinc is an important component of many kinds of batteries. This metal is mined as zinc compounds, one of which is zinc carbonate. To obtain the pure metal, the ore must go through the following chemical processes:.

Lots of volcanoes form along which boundaries?

geyser plate boundaries

deposit plate bounderies

basalt plate boundaries

subduction plate boundaries

Lots of volcanoes form along subduction plate boundaries. The edges of the Pacific Plate are a long subduction boundary. Lines of volcanoes can form at subduction zones on oceanic or continental crust. Japan is an example of a volcanic arc on oceanic crust. The Cascade Range and Andes Mountains are volcanic arcs on continental crust.

Which body organ filters the blood in the body and creates urine?

the arteries

intestines

liver

the kidneys

The kidneys help the body maintain homeostasis in several ways. They filter all the blood in the body many times each day and produce urine. They control the amount of water and dissolved substances in the blood by excreting more or less of them in urine.

Compared with the molecules of many other substances, molecules of water are strongly attracted to what?

nothing

hydrogen

helium

each other

Compared with the molecules of many other substances, molecules of water are strongly attracted to each other. How is this likely to affect the boiling point of water?.

Greater reflection off what atmospheric layer allows am radio waves to travel even farther at night than they can during the day?

troposphere

stratosphere

exosphere

ionosphere

A: With greater reflection off the ionosphere, AM waves can travel even farther at night than they can during the day. Radio receivers can often pick up radio broadcasts at night from cities that are hundreds of miles away.

Earth spinning as air moves over its surface causes what?

axial tilt

seasons

centrifugal effect

coriolis effect

Earth is spinning as air moves over its surface. This causes the Coriolis effect. Winds blow on a diagonal over the surface due to Coriolis effect. From which direction do the northern trade winds blow?.

Beryllium hydride consists of a central beryllium atom with two single bonds to what?

calcium atoms

nitrogen atoms

metabolic atoms

hydrogen atoms

Beryllium hydride consists of a central beryllium atom with two single bonds to hydrogen atoms. Recall that it violates the octet rule.

Amides are actually formed by bringing together an amine-containing molecule and molecule containing what?

Fatty acid

oxidize acid

polymer acid

carboxylic acid

Amides are actually formed by bringing together an amine-containing molecule and a carboxylic acidcontaining molecule. A molecule of H2O is lost, much like when an ester forms:.

What are long living plasma cells called?

brain Cells

device cells

context cells

memory cells

Most plasma cells live for just a few days, but some of them live much longer. They may even survive for the lifetime of the individual. Long-living plasma cells are called memory cells. They retain a “memory” of a specific pathogen long after an infection is over. They help launch a rapid response against the pathogen if it invades the body again in the future.

When do homologous chromosomes separate and go to different gametes?

after meiosis

during electrolysis

before meiosis

during meiosis

During meiosis, homologous chromosomes separate and go to different gametes. Thus, the two alleles for each gene also go to different gametes. At the same time, different chromosomes assort independently. As a result, alleles for different genes assort independently as well. In these ways, alleles are shuffled and recombined in each parent’s gametes.

What type of cells are often the product of normal cells that have lost the ability to regulate the cell cycle?

sick cells

corrosive cells

uncontrolled cells

cancerous cells

Many cancerous cells are the products of normal cells that have lost the ability to regulate the cell cycle. The genes that encode the proteins involved in cell cycle regulation have mutations. One category of genes, called oncogenes, accelerate the cell cycle. Some cancers can be inherited, such as breast cancer (due to mutations in the BRCA1 and BRCA2 genes). Approximately five to ten percent of cancers are entirely hereditary. Other cancers are triggered by an environmental stimulus, such as through the relationship between tobacco smoke and lung cancer, or ultraviolet radiation and skin cancer.

Which ductless gland releases secretions directly into surrounding tissues and fluids?

adrenal glands

marrow gland

pineal gland

endocrine gland

Glandular Epithelium A gland is a structure made up of one or more cells modified to synthesize and secrete chemical substances. Most glands consist of groups of epithelial cells. A gland can be classified as an endocrine gland, a ductless gland that releases secretions directly into surrounding tissues and fluids (endo- = “inside”), or an exocrine gland whose secretions leave through a duct that opens directly, or indirectly, to the external environment (exo- = “outside”).

When different types of tissues work together to perform a unique function, what do they form?

produce

organs

Brian

organ

Plant Organ Systems In plants, just as in animals, similar cells working together form a tissue. When different types of tissues work together to perform a unique function, they form an organ; organs working together form organ systems. Vascular plants have two distinct organ systems: a shoot system, and a root system. The shoot system consists of two portions: the vegetative (nonreproductive) parts of the plant, such as the leaves and the stems, and the reproductive parts of the plant, which include flowers and fruits. The shoot system generally grows above ground, where it absorbs the light needed for photosynthesis. The root system, which supports the plants and absorbs water and minerals, is usually underground. Figure 30.2 shows the organ systems of a typical plant.

Over 90% of the energy we use comes originally from what?

horizon

earth

water

sun

Over 90% of the energy we use comes originally from the sun. Every day, the sun provides the earth with almost 10,000 times the amount of energy necessary to meet all of the world’s energy needs for that day. Our challenge is to find ways to convert and store incoming solar energy so that it can be used in reactions or chemical processes that are both convenient and nonpolluting. Plants and many bacteria capture solar energy through photosynthesis. We release the energy stored in plants when we burn wood or plant products such as ethanol. We also use this energy to fuel our bodies by eating food that comes directly from plants or from animals that got their energy by eating plants. Burning coal and petroleum also releases stored solar energy: These fuels are fossilized plant and animal matter. This chapter will introduce the basic ideas of an important area of science concerned with the amount of heat absorbed or released during chemical and physical changes—an area called thermochemistry. The concepts introduced in this chapter are widely used in almost all scientific and technical fields. Food scientists use them to determine the energy content of foods. Biologists study the energetics of living organisms, such as the metabolic combustion of sugar into carbon dioxide and water. The oil, gas, and transportation industries, renewable energy providers, and many others endeavor to find better methods to produce energy for our commercial and personal needs. Engineers strive to improve energy efficiency, find better ways to heat and cool our homes, refrigerate our food and drinks, and meet the energy and cooling needs of computers and electronics, among other applications. Understanding thermochemical.

What term is used to describe an illusion that light from faraway objects is reflected by a pool of water that is not really there?

Mirror

version

prototype

mirage

The most common type of mirage is an illusion that light from faraway objects is reflected by a pool of water that is not really there. Mirages are generally observed in deserts, when there is a hot layer of air near the ground. Given that the refractive index of air is lower for air at higher temperatures, explain how mirages can be formed.

How do prokaryotes reproduce?

unusually

inorganically

sexually

asexually

What does hemoglobin in blood carry to the cells?

nitrogen

methane

carbon dioxide

oxygen

Figure 39.19 The protein inside (a) red blood cells that carries oxygen to cells and carbon dioxide to the lungs is (b) hemoglobin. Hemoglobin is made up of four symmetrical subunits and four heme groups. Iron associated with the heme binds oxygen. It is the iron in hemoglobin that gives blood its red color.

Surface tension comes from the fact that particles at the surface of a liquid do not experience interactions from all directions which leads to what on the surface?

waves

degradation of forces

floating particles

imbalance of forces

Surface tension comes from the fact that particles at the surface of a liquid do not experience interactions from all directions, leading to an imbalance of forces on the surface. Surface tension is responsible for several well-known behaviors of liquids, including water. Liquids with high surface tension tend to bead up when present in small amounts ( - ball-ch10_s03_f06). Surface.

Where do biochemical reactions occer?

in the environment

outside organisms

inside labs

inside organisms

Biochemical reactions are chemical reactions that take place inside living things. Two of the most important biochemical reactions are photosynthesis and cellular respiration.

What type of behavior has the advantage of being flexible and capable of changing to suit changing conditions?

saved behavior

inherited behavior

noted behavior

learned behavior

Most animals are capable of learning, but animals that are more intelligent are better at learning and depend more on learned behaviors. The big advantage of learned behaviors over innate behaviors is that learned behaviors are flexible. They can be changed to suit changing conditions.

This process breaks rocks and other surface materials into much smaller pieces?

chemical reaction

corrosion

leaching

weathering

What is the main element in organic compounds?

nitrogen

hydrogen

oxygen

carbon

Carbon is the main element in organic compounds. Carbon can form stable bonds with many elements, including itself.

What is the basic unit of matter?

ions

neutrons

calories

atoms

The basic unit of matter is an atom . At the center of an atom is its nucleus . Protons are positively charged particles in the nucleus. Also in the nucleus are neutrons with no electrical charge. Orbiting the nucleus are tiny electrons. Electrons are negatively charged. An atom with the same number of protons and electrons is electrically neutral. If the atom has more or less electrons to protons it is called an ion . An ion will have positive charge if it has more protons than electrons. It will have negative charge if it has more electrons than protons.

What theory proposes that microorganisms are the cause of many diseases?

mutated theory

malignant theory

evolution theory

germ theory

The germ theory proposes that microorganisms are the cause of many diseases.

Water is a polar compound, so its molecules are attracted to each other and form what kind of bonds?

helium

mixed

carbon

hydrogen

Water is a polar compound, so its molecules are attracted to each other and form hydrogen bonds.

What is the term for a substance that causes the speed of a reaction to increase?

monite

indicate

component

catalyst

A catalyst is a substance that increases the speed of a reaction. Overall, a catalyst is not a reactant and is not used up, but it still affects how fast a reaction proceeds. However, a catalyst does not affect the extent or position of a reaction at equilibrium. It helps a reaction achieve equilibrium faster.

What is it called when rays focus at different distances from the lens?

angular aberration

constant aberration

carbon aberration

spherical aberration

Figure 26.30 Spherical aberration is caused by rays focusing at different distances from the lens.

Brass and bronze are examples of what type of mixture composed of two or more elements, at least one of which is a metal?

metalloid

halloid

compound

alloy

An alloy is a mixture composed of two or more elements, at least one of which is a metal. You are probably familiar with some alloys such as brass and bronze. Brass is an alloy of copper and zinc. Bronze is an alloy of copper and tin. Alloys are commonly used in manufactured items because the properties of these metal mixtures are often superior to a pure metal. Bronze is harder than copper and more easily cast. Brass is very malleable and its acoustic properties make it useful for musical instruments.

What is a region of repetitive noncoding nucleotide sequences at each end of a chromosome?

cytoskeleton

diploid

cellular

telomere

Reverse transcription also occurs with retrotransposons and during telomere synthesis in eukaryotes. Retrotransposons are self-replicating segments of eukaryotic genomes that use reverse transcriptase to move from one position in the genome to another via a RNA intermediate. A telomere is a region of repetitive noncoding nucleotide sequences at each end of a chromosome. These sequences protect the end of the chromosome from deterioration or from fusion with neighboring chromosomes. Each time DNA is replicated, small segments of DNA from the ends of the chromosome is lost. Telomerase is a reverse transcriptase that uses an RNA intermediate to elongate the 3' end of DNA strands in the telomere regions after each replication cycle.

What is the color of mercury oxide?

green

yellow

orange

red

Mercury(II) oxide is a red solid. When it is heated, it decomposes into mercury metal and oxygen gas.

At a convergent plate boundary, when one plate is oceanic, there are large what?

earthquakes

plateaus

lakes

volcanoes

At a convergent plate boundary, when one plate is oceanic, there are large volcanoes. These volcanoes are found in lines that outline the subduction zone. Earthquakes also happen in these zones. The Aleutian Islands that border southern Alaska are an island arc. In this winter image from space, the volcanoes are covered with snow.

What is the term for the wavelengths of light humans can see?

distinct light

radiation

ultraviolet light

visible light

Visible light is the wavelengths of light humans can see.

What is the charge on a single electron known as?

fundamental charge

basic charge

electron charge

elementary charge

The charge on a single electron is and is known as the elementary charge.

What mineral that occurs in bones helps combat osteoporosis?

potassium

magnesium

iron

calcium

Osteoporosis is a disease in which bones lose mass and become more fragile than they should be. Osteoporosis also makes bones more likely to break. Two of the easiest ways to prevent osteoporosis are eating a healthy diet that has the right amount of calcium and vitamin D and to do some sort of weight-bearing exercise every day. Foods that are a good source of calcium include milk, yogurt, and cheese. Non-dairy sources of calcium include Chinese cabbage, kale, and broccoli. Many fruit juices, fruit drinks, tofu, and cereals have calcium added to them. It is recommended that teenagers get 1300 mg of calcium every day. For example, one cup (8 fl. oz. ) of milk provides about 300 mg of calcium, or about 30% of the daily requirement. Other sources of calcium are pictured in the Figure below .

When the wind deposits sand, it forms small hills, what are these hills called?

mud puddles

sand tunnels

snow banks

sand dunes

When the wind deposits sand, it forms small hills. These hills are called sand dunes ( Figure below ). For sand dunes to form, there must be plenty of sand and wind. Sand dunes are found mainly in deserts and on beaches.

Carboxylic acids have an acidic hydrogen atom, but esters do not. what do esters have in place of an acidic hydrogen atom?

crystallization group

synthesis group

carbonation group

hydrocarbon group

Unlike ethers, esters have a carbonyl group. Unlike carboxylic acids, esters have no acidic hydrogen atom; they have a hydrocarbon group in its place.

Latitude, humidity, and elevation affect the type of what, a term for a large naturally occurring community?

climate

territory

ecosystem

biome

Factors affecting biome type include latitude, humidity, and elevation.

The distance between two crests of a wave of light is referred to as what, which is related to the color of light?

bandwidth

magnitude

spectrum

wavelength

wavelength : The distance between two crests of a wave of light. The color of light is related to its wavelength. This is inversely proportional to frequency.

What is the basic unit of structure and function in all organisms?

the electron

the atom

the neutron

the cell

The cell is the basic unit of structure and function of all organisms. The Cell Theory states that all living things are made of one or more cells, or the secretions of those cells, such as the organisms shown in Figure below . For example, shell and bone are built by cells from substances that they secrete into their surroundings. Cells come from cells that already exist, that is, they do not suddenly appear from nowhere. In organisms that are made of many cells (called multicellular organisms), every cell in the organism's body derives from the single cell that results from a fertilized egg. You will learn more about cells and the Cell Theory in Cells: The Cell Theory (Advanced) concept.

Which organ in the human body filters blood and excretes urine?

the thyroid

the liver

the bladder

the kidney

The kidneys filter all the blood in the body many times each day and produce a total of about 1.5 liters of urine . The kidneys control the amount of water, ions, and other substances in the blood by excreting more or less of them in urine. The kidneys also secrete hormones that help maintain homeostasis. Erythropoietin , for example, is a kidney hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete renin, which regulates blood pressure, and calcitriol, the active form of vitamin D, which helps maintain calcium for bones. The kidneys themselves are also regulated by hormones. For example, antidiuretic hormone from the hypothalamus stimulates the kidneys to produce more concentrated urine when the body is low on water.

Sugars are simple types of what biochemical compounds and possess relatively small molecules?

lipids

proteins

vegetables

carbohydrates

Carbohydrates are biochemical compounds that include sugar, starch, glycogen, and cellulose. Sugars are simple carbohydrates with relatively small molecules. Glucose is one of the smallest sugar molecules. Its chemical formula is C 6 H 12 O 6 . This means that a molecule of glucose contains 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose can obtain it by consuming plants or organisms that consume plants.

What type of tissue is blood?

nervous

muscular

epithelial

connective

Blood Blood is considered a connective tissue because it has a matrix, as shown in Figure 33.17. The living cell types are red blood cells (RBC), also called erythrocytes, and white blood cells (WBC), also called leukocytes. The fluid portion of whole blood, its matrix, is commonly called plasma.

What is the force that causes objects to fall down to the ground?

motion

velocity

pull

gravity

Regardless of what gravity is — a force between masses or the result of curves in space and time — the effects of gravity on motion are well known. You already know that gravity causes objects to fall down to the ground. Gravity affects the motion of objects in other ways as well.

The distance of stars is measured in what terms, meaning the light takes many thousands of years to reach us?

light hours

light months

light decades

light years

Viewing distant stars is looking back in time. The stars we see are many thousands of light years away, which means the light takes many thousands of years to reach us. Thus the stars we see in the sky are how they looked thousands of years ago.

What type of matter often sinks into cracks between rocks?

energy

algae

vapor

liquid

Name a one-celled organism that can be found on your skin, in the ground, or in all different types of water.

pathogens

virus

fungus

bacteria

Cells are found in all different types of environments, and these environments are constantly changing. For example, one-celled organisms, like bacteria, can be found on your skin, in the ground, or in all different types of water. Therefore, cells need a way to protect themselves. This job is done by the cell membrane, which is also known as the plasma membrane.

What type of power is generated using a nonrenewable resource?

water power

wind power

solar power

nuclear power

Chuck Szmurlo (Wikimedia: Cszmurlo). Nuclear power is generated using a nonrenewable resource . CC BY 2.5.

The earth is tilted on its what?

radius

top

compass

axis

The Earth is tilted on its axis ( Figure above ). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day ( Figure below ).

What can human facial expressions communicate?

theories

behaviors

ideas

emotions

Human facial expressions can communicate a range of emotions.