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What kind of cell is a cell with two chromosomes? | neurotic cell | haploid cells | mutated cell | diploid cell | |
Which term literally means 'spore in a vessel'? | cyanobacteria | Carboid | germination | sporangia | to the embryo as it develops into the new generation of sporophyte. This distinguishing feature of land plants gave the group its alternate name of embryophytes. Sporangia in Seedless Plants The sporophyte of seedless plants is diploid and results from syngamy (fusion) of two gametes. The sporophyte bears the sporangia (singular, sporangium): organs that first appeared in the land plants. The term “sporangia” literally means “spore in a vessel,” as it is a reproductive sac that contains spores Figure 25.3. Inside the multicellular sporangia, the diploid sporocytes, or mother cells, produce haploid spores by meiosis, where the 2n chromosome number is reduced to 1n (note that many plant sporophytes are polyploid: for example, durum wheat is tetraploid, bread wheat is hexaploid, and some ferns are 1000-ploid). The spores are later released by the sporangia and disperse in the environment. Two different types of spores are produced in land plants, resulting in the separation of sexes at different points in the lifecycle. Seedless nonvascular plants produce only one kind of spore and are called homosporous. The gametophyte phase is dominant in these plants. After germinating from a spore, the resulting gametophyte produces both male and female gametangia, usually on the same individual. In contrast, heterosporous plants produce two morphologically different types of spores. The male spores are called microspores, because of their smaller size, and develop into the male gametophyte; the comparatively larger megaspores develop into the female gametophyte. Heterospory is observed in a few seedless vascular plants and in all seed plants. |
Human culture is related to evolutionary theory in the discipline of what? | ethnology | astrology | psychopathology | sociobiology | |
Which forces hold particles together in more ordered states? | particular | natural | gravitational | intermolecular | Chemical energy, the energy stored in molecules and atoms, is one type of potential energy. Certain reactions can cause this energy to be released as heat. Other reactions require an input of energy, in which case the products will store more potential energy than the reactants. When we studied phase changes, we saw a relationship between energy and the state of matter. To melt a solid or boil a liquid, energy needs to be added in order to break up the intermolecular forces holding particles together in more ordered states. The reverse processes, condensation and freezing, release energy, because more favorable intermolecular interactions are formed. |
What is the movement of muscle in the digestive system called? | apoptosis | acid reflux | labor contractions | peristalsis | The organs of the digestive system are lined with muscles. The muscles contract, or tighten, to push food through the system ( Figure below ). The muscles contract in waves. The waves pass through the digestive system like waves through a slinky. This movement of muscle contractions is called peristalsis . Without peristalsis, food would not be able to move through the digestive system. Peristalsis is an involuntary process, which means that it occurs without your conscious control. |
Smoking increases the risk of cancer from what radioactive gas that can also be detected with a test kit for your home? | carbon dioxide | arsenic | carbon monoxide | radon | Radon is also radioactive and can easily be inhaled into the lungs. Over time, this internal radon exposure can lead to the development of lung cancer. The incidence of lung cancer in smokers exposed to radon is much higher than that in non-smokers exposed to radon since smoking has already produced some lung damage, and the radon simply makes the damage worse. Radon exposure is highest in homes lacking good air circulation to move the gas out of the residence. There are a number of inexpensive approaches to decreasing your exposure to radon. A good start is to test your living area for radon with a radon test kit. |
What is the main function of the cardiovascular system? | respiration | implanatation | digestion | to transport | Many ecosystems have changed because of human actions. The human species is responsible for a range of environmental problems. |
When something is described as "hydrophilic", you can determine something about how it interacts with what? | iron | hydrogen | air | water | hydrophilic heads are directed outward, in contact with the water. Each micelle may contain thousands of lipid molecules. Polar lipids may also form a monolayer, a layer one molecule thick on the surface of the water. The polar heads face into water, and the nonpolar tails stick up into the air. Bilayers are double layers of lipids arranged so that the hydrophobic tails are sandwiched between an inner surface and an outer surface consisting of hydrophilic heads. The hydrophilic heads are in contact with water on either side of the bilayer, whereas the tails, sequestered inside the bilayer, are prevented from having contact with the water. Bilayers like this make up every cell membrane (Figure 17.6 "Schematic Diagram of a Cell Membrane"). Figure 17.5 Spontaneously Formed Polar Lipid Structures in Water: Monolayer, Micelle, and Bilayer. |
What human traits are controlled by more than one gene? | maladaptive traits | mutant traits | autolysis traits | polygenic traits | Many human traits are controlled by more than one gene. These traits are called polygenic traits (or characteristics). The alleles of each gene have a minor additive effect on the phenotype. There are many possible combinations of alleles, especially if each gene has multiple alleles. Therefore, a whole continuum of phenotypes is possible. |
Most chromosomal disorders involve which chromosomes? | protosomes | autosomes | ribosomes | sex chromosomes | Most chromosomal disorders involve the sex chromosomes. Can you guess why? The X and Y chromosomes are very different in size. The X is much larger than the Y. This difference in size creates problems. It increases the chances that the two chromosomes will fail to separate properly during meiosis. |
Carbonic anhydrase plays what role to achieve a variety of results involving different organs? | inhibition | blocker | sequence | enzyme | About 67 percent of the water, Na+, and K+ entering the nephron is reabsorbed in the PCT and returned to the circulation. Almost 100 percent of glucose, amino acids, and other organic substances such as vitamins are normally recovered here. Some glucose may appear in the urine if circulating glucose levels are high enough that all the glucose transporters in the PCT are saturated, so that their capacity to move glucose is exceeded (transport maximum, or Tm). In men, the maximum amount of glucose that can be recovered is about 375 mg/min, whereas in women, it is about 300 mg/min. This recovery rate translates to an arterial concentration of about 200 mg/dL. Though an exceptionally high sugar intake might cause sugar to appear briefly in the urine, the appearance of glycosuria usually points to type I or II diabetes mellitus. The transport of glucose from the lumen of the PCT to the interstitial space is similar to the way it is absorbed by the small intestine. Both glucose and Na+ bind simultaneously to the same symport proteins on the apical surface of the cell to be transported in the same direction, toward the interstitial space. Sodium moves down its electrochemical and concentration gradient into the cell and takes glucose with it. Na+ is then actively pumped out of the cell at the basal surface of the cell into the interstitial space. Glucose leaves the cell to enter the interstitial space by facilitated diffusion. The energy to move glucose comes from the Na+/K+ ATPase that pumps Na+ out of the cell on the basal surface. Fifty percent of Cl– and variable quantities of Ca++, Mg++, and HPO 24 − are also recovered in the PCT. Recovery of bicarbonate (HCO3–) is vital to the maintenance of acid–base balance, since it is a very powerful and fast-acting buffer. An important enzyme is used to catalyze this mechanism: carbonic anhydrase (CA). This same enzyme and reaction is used in red blood cells in the transportation of CO2, in the stomach to produce hydrochloric acid, and in the pancreas to produce HCO3– to buffer acidic chyme from the stomach. In the kidney, most of the CA is located within the cell, but a small amount is bound to the brush border of the membrane on the apical surface of the cell. In the lumen of the PCT,. |
What is it called when minerals replace the organic material to create fossils? | petrification | carbonization | spongin | permineralization | Some fossils are created when minerals replace the organic material. This is called permineralization. |
Smaller sized galaxies are known as what? | constellations | nebula | black holes | dwarf galaxies | Dwarf galaxies are small galaxies containing “only” a few million to a few billion stars. Most dwarf galaxies are irregular in shape. However, there are also dwarf elliptical galaxies and dwarf spiral galaxies . Dwarf galaxies are the most common type in the Universe. However, because they are relatively small and dim, we don’t see as many dwarf galaxies as we do their full-sized cousins. |
What is the name of the supportive structed that helps move a worm's muscles? | pollenation | spongin | exoskeleton | hydroskeleton | Segmented worms have a well-developed body cavity filled with fluid. This fluid-filled cavity serves as a hydroskeleton , a supportive structure that helps move the worm's muscles. Only the most primitive worms (the flatworms) lack a body cavity. |
What type of transport occurs when substances cross the plasma membrane without any input of energy from the cell? | active transport | physical transport | wave diffusion | passive transport | Passive transport occurs when substances cross the plasma membrane without any input of energy from the cell. No energy is needed because the substances are moving from an area where they have a higher concentration to an area where they have a lower concentration. Concentration refers to the number of particles of a substance per unit of volume. The more particles of a substance in a given volume, the higher the concentration. A substance always moves from an area where it is more concentrated to an area where it is less concentrated. It’s a little like a ball rolling down a hill. It goes by itself without any input of extra energy. |
A mold is an imprint of an organism left in what? | fossil | magma | band | rock | Fossils may form in other ways. With complete preservation, the organism doesn't change much. As seen below, tree sap may cover an organism and then turn into amber. The original organism is preserved so that scientists might be able to study its DNA. Organisms can also be completely preserved in tar or ice. Molds and casts are another way organisms can be fossilized. A mold is an imprint of an organism left in rock. The organism's remains break down completely. Rock that fills in the mold resembles the original remains. The fossil that forms in the mold is called a cast. Molds and casts usually form in sedimentary rock. With compression, an organism's remains are put under great pressure inside rock layers. This leaves behind a dark stain in the rock. |
Particles of different densities exert different amounts of what? | energy | resistance | force | pressure | Christopher Auyeung. Particles of different densities exert different amounts of pressure . CC BY-NC 3.0. |
Plants generally transport carbohydrates from leaves to roots and other nonphotosynthetic organs in the form of what? | chloride | glucose | potassium | sucrose | |
Monocots and eudicots differ in what type of a leaf's tissue? | reproductive | structural | circulatory | vascular | |
What kind of reproduction, in general, relies on sets of cells that are precursors for eggs and sperm? | asexual | binary fission | fusion | sexual | |
A lens of what shape causes rays of light to diverge, or spread apart, as they pass through it? | elongated | convex | flat | concave | A concave lens is thicker at the edges than it is in the middle. You can see the shape of a concave lens in the Figure below . From the diagram, it’s clear that the lens causes rays of light to diverge, or spread apart, as they pass through it. Note that the image formed by a concave lens is on the same side of the lens as the object. It is also smaller than the object and right-side up. However, it isn’t a real image. It is a virtual image. Your brain “tricks” you into seeing an image there. The light rays actually pass through the glass to the other side and spread out in all directions. You can explore the formation of images by a concave lens at this URL: http://phet. colorado. edu/sims/geometric-optics/geometric-optics_en. html. |
What is the complex network of nervous tissue that carries electrical messages throughout the body? | lymphatic system | respiratory system | circulatory system | nervous system | A small child darts in front of your bike as you race down the street. You see the child and immediately react. You put on the brakes, steer away from the child, and yell out a warning, all in just a split second. How do you respond so quickly? Such rapid responses are controlled by your nervous system. The nervous system is a complex network of nervous tissue that carries electrical messages throughout the body. It includes the brain and spinal cord, the central nervous system , and nerves that run throughout the body, the peripheral nervous system (see Figure below ). To understand how nervous messages can travel so quickly, you need to know more about nerve cells. |
Crowding and resource limitation can have a profound effect on the rate of what? | cultural advances | population stagnation | technology advances | population growth | |
X and y are the labels of what specialized human chromosomes? | protein chromosomes | carb chromosomes | exotic chromosomes | sex chromosomes | The 24 human chromosomes. The autosomes are numbered 1 - 22, based on size, with chromosome 1 being the largest. The X and Y sex chromosomes are shown in the box. |
Isotopes are named for their number of ______ plus neutrons? | nuclei | electrons | atoms | protons | Isotopes are named for their number of protons plus neutrons. If a carbon atom had 7 neutrons, what would it be named?. |
Because fungi feed on decaying and dead matter, they play what important role by releasing essential elements into the environment? | consumers | producers | carnivores | decomposers | CHAPTER SUMMARY 24.1 Characteristics of Fungi Fungi are eukaryotic organisms that appeared on land more than 450 million years ago. They are heterotrophs and contain neither photosynthetic pigments such as chlorophyll, nor organelles such as chloroplasts. Because fungi feed on decaying and dead matter, they are saprobes. Fungi are important decomposers that release essential elements into the environment. External enzymes digest nutrients that are absorbed by the body of the fungus, which is called a thallus. A thick cell wall made of chitin surrounds the cell. Fungi can be unicellular as yeasts, or develop a network of filaments called a mycelium, which is often described as mold. Most species multiply by asexual and sexual reproductive cycles and display an alternation of generations. Another group of fungi do not have a sexual cycle. Sexual reproduction involves plasmogamy (the fusion of the cytoplasm), followed by karyogamy (the fusion of nuclei). Meiosis regenerates haploid individuals, resulting in haploid spores. |
If the temperature of a gas sample is decreased, what happens to the volume? | expands | increases | stays the same | decreases | If the temperature of a gas sample is decreased, the volume decreases as well. |
Most food chains and webs have a maximum of how many trophic levels? | 6 | 3 | 10 | 4 | A trophic level is a feeding position in a food chain or food web. Most food chains and webs have a maximum of four trophic levels. There is less energy and biomass at higher trophic levels. |
What refers to the development and nourishment of an embryo within the mother’s body but not inside an egg? | ovulation | birth | adolescence | vivipary | Vivipary refers to the development and nourishment of an embryo within the mother’s body but not inside an egg. Birth may be followed by a period of parental care of the offspring. This reproductive strategy occurs in almost all mammals including humans. |
What kind of anaerobe is yeast? | aerobic | mutualistic | obligate | facultative | Yeast is a facultative anaerobe. This means that alcohol fermentation takes place only if: a. the temperature is close to 37°C b. the atmosphere does not contain oxygen c. sugar is provided to the cells d. light is provided to the cells. |
Bones are far from static, or unchanging. instead, they are what? | fluid | continuous | stable | dynamic | Bones are far from static, or unchanging. Instead, they are dynamic, living tissues that are constantly being reshaped. Under the direction of osteocytes, osteoblasts continuously build up bone, while osteoclasts continuously break it down. You can watch an animated video of these processes in bone at http://www. youtube. com/watch?v=yENNqRJ2mu0 . |
After entering the circulation, approximately one-third of platelets migrate to what organ for storage, to be released in response to any blood vessel rupture? | kidneys | bladder | lungs | spleen | Platelets You may occasionally see platelets referred to as thrombocytes, but because this name suggests they are a type of cell, it is not accurate. A platelet is not a cell but rather a fragment of the cytoplasm of a cell called a megakaryocyte that is surrounded by a plasma membrane. Megakaryocytes are descended from myeloid stem cells (see Figure 18.4) and are large, typically 50–100 µm in diameter, and contain an enlarged, lobed nucleus. As noted earlier, thrombopoietin, a glycoprotein secreted by the kidneys and liver, stimulates the proliferation of megakaryoblasts, which mature into megakaryocytes. These remain within bone marrow tissue (Figure 18.12) and ultimately form platelet-precursor extensions that extend through the walls of bone marrow capillaries to release into the circulation thousands of cytoplasmic fragments, each enclosed by a bit of plasma membrane. These enclosed fragments are platelets. Each megakarocyte releases 2000–3000 platelets during its lifespan. Following platelet release, megakaryocyte remnants, which are little more than a cell nucleus, are consumed by macrophages. Platelets are relatively small, 2–4 µm in diameter, but numerous, with typically 150,000–160,000 per µL of blood. After entering the circulation, approximately one-third migrate to the spleen for storage for later release in response to any rupture in a blood vessel. They then become activated to perform their primary function, which is to limit blood loss. Platelets remain only about 10 days, then are phagocytized by macrophages. Platelets are critical to hemostasis, the stoppage of blood flow following damage to a vessel. They also secrete a variety of growth factors essential for growth and repair of tissue, particularly connective tissue. Infusions of concentrated platelets are now being used in some therapies to stimulate healing. |
What causes a small scrap of paper placed on top of the water droplet to float , although the object is denser (heavier) than the water? | van der waals force | diffusion | transfusion | surface tension | a small scrap of paper onto a droplet of water, the paper floats on top of the water droplet, although the object is denser (heavier) than the water. This occurs because of the surface tension that is created by the water molecules. Cohesion and surface tension keep the water molecules intact and the item floating on the top. It is even possible to “float” a steel needle on top of a glass of water if you place it gently, without breaking the surface tension (Figure 2.11). |
What is the term for a structure composed of more than one type of tissue? | cortex | marrow | system | organ | Like animals, plants have organs that are specialized to carry out complex functions. An organ is a structure composed of more than one type of tissue. A tissue, in turn, is a group of cells of the same kind that do the same job. In this lesson, you will read about the tissues that do the important work of plants. The cells that make up plant tissues are described first. |
What is the pair of bean-shaped organs situated just above the waist? | lungs | pancreas | aorta | kidneys | The kidneys are a pair of bean-shaped organs just above the waist. A cross-section of a kidney is shown in Figure below . The function of the kidney is to filter blood and form urine. Urine is the liquid waste product of the body that is excreted by the urinary system. Nephrons are the structural and functional units of the kidneys. A single kidney may have more than a million nephrons!. |
What part of a bird is adapted for the food it eats? | eye | teeth | head | beak | Bird beaks are generally adapted for the food they eat. For example, the sharp, hooked beak of a raptor is well suited for killing and tearing apart prey. The long beak of the hummingbird in Figure below co-evolved with the tube-shaped flowers from which it sips nectar. |
What is the inner cell mass formed by the cells of the blastocyst called? | ectoderm | xerophyte | amniotic cavity | embryoblast | The cells of the blastocyst form an inner cell mass and an outer cell layer, as shown in Figure below . The inner cell mass is called the embryoblast . These cells will soon develop into an embryo. The outer cell layer is called the trophoblast . These cells will develop into other structures needed to support and nourish the embryo. |
What does the distribution of darts on a dartboard shows the difference between? | equilibrium and precision | production and precision | Aim and precision | accuracy and precision | The distribution of darts on a dartboard shows the difference between accuracy and precision. |
What gas do the lungs give up as they take in oxygen? | nitrogen | carbon monoxide | methane | carbon dioxide | Pulmonary circulation is the part of the circulatory system that carries blood between the heart and lungs (the term “pulmonary” means “of the lungs”). It is illustrated in Figure below . Deoxygenated blood leaves the right ventricle through pulmonary arteries, which transport it to the lungs. In the lungs, the blood gives up carbon dioxide and picks up oxygen. The oxygenated blood then returns to the left atrium of the heart through pulmonary veins. |
What is the term for the last stage of life before adulthood? | childhood | old age | pre-pubescence | adolescence | For the first year after birth, a baby is called an infant . Childhood begins at age two and continues until adolescence. Adolescence is the last stage of life before adulthood. |
Breaking of weak bonds, which tend to form between positive and negative charges, does not require much what? | time | catalyzation | heat | energy | Hydrogen Bonds Ionic and covalent bonds are strong bonds that require considerable energy to break. However, not all bonds between elements are ionic or covalent bonds. Weaker bonds can also form. These are attractions that occur between positive and negative charges that do not require much energy to break. Two weak bonds that occur frequently are hydrogen bonds and van der Waals interactions. These bonds give rise to the unique properties of water and the unique structures of DNA and proteins. When polar covalent bonds containing a hydrogen atom form, the hydrogen atom in that bond has a slightly positive charge. This is because the shared electron is pulled more strongly toward the other element and away from the hydrogen nucleus. Because the hydrogen atom is slightly positive (δ+), it will be attracted to neighboring negative partial charges (δ–). When this happens, a weak interaction occurs between the δ+ charge of the hydrogen atom of one molecule and the δ– charge of the other molecule. This interaction is called a hydrogen bond. This type of bond is common; for example, the liquid nature of water is caused by the hydrogen bonds between water molecules (Figure 2.7). Hydrogen bonds give water the unique properties that sustain life. If it were not for hydrogen bonding, water would be a gas rather than a liquid at room temperature. |
What two organs secrete fluids that aid in digestion? | spleen and bladder | kidney and gall bladder | stomach and lung | pancreas and liver | The pancreas and liver secrete fluids that aid in digestion. |
When light meets matter, it may be reflected, transmitted, or what? | diffracted | diffuse | reflected | absorbed | |
When a sperm penetrates the egg, it triggers the egg to complete what? | lesions | mutations | fertilization | meiosis | When a sperm penetrates the egg, it triggers the egg to complete meiosis. The sperm also undergoes changes. Its tail falls off, and its nucleus fuses with the nucleus of the egg. The resulting cell, called a zygote, contains all the chromosomes needed for a new human organism. Half the chromosomes come from the egg and half from the sperm. |
What chromosome determines the sex of an organism? | autosome | ribosome | S chromosome | sex chromosome | A sex chromosome is a chromosome that determines the sex of an organism. Humans have two sex chromosomes, X and Y . Females have two X chromosomes ( XX ), and males have one X and one Y chromosome ( XY ). An autosome is any chromosome other than a sex chromosome. If a trait is autosomal it will affect males and females equally. |
In contrast to precision, this term means how close a measurement is to the correct or accepted value of the quantity being measured? | deviant | diversity | frequency | accuracy | In everyday speech, the terms accuracy and precision are frequently used interchangeably. However, their scientific meanings are quite different. Accuracy is a measure of how close a measurement is to the correct or accepted value of the quantity being measured. Precision is a measure of how close a series of measurements are to one another. Precise measurements are highly reproducible, even if the measurements are not near the correct value. |
Where is most of the cell's dna contained? | cell membrane | vacuole | epidermis | nucleus | Although most of a cell's DNA is contained in the cell nucleus, mitochondria have their own DNA. Mitochondria also have the machinery to manufacture their own RNAs and proteins. The human mitochondrial DNA sequence has 16,569 base pairs encoding 37 total genes: 22 tRNA genes, 2 rRNA genes, and 13 peptide genes. The 13 mitochondrial peptides in humans are integrated into the inner mitochondrial membrane, along with proteins encoded by nuclear genes. |
The four major classes of biological macromolecules include carbohydrates, lipids, proteins, and what else? | structural acids | liquids | fats | nucleic acids | 3.1 | Synthesis of Biological Macromolecules By the end of this section, you will be able to: • Understand the synthesis of macromolecules • Explain dehydration (or condensation) and hydrolysis reactions As you’ve learned, biological macromolecules are large molecules, necessary for life, that are built from smaller organic molecules. There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids); each is an important cell component and performs a wide array of functions. Combined, these molecules make up the majority of a cell’s dry mass (recall that water makes up the majority of its complete mass). Biological macromolecules are organic, meaning they contain carbon. In addition, they may contain hydrogen, oxygen, nitrogen, and additional minor elements. |
What protects you from pathogens and keeps you healthy? | potent system | immunity system | health system | immune system | Your immune system usually protects you from pathogens and keeps you well. However, like any other body system, the immune system itself can develop problems. Sometimes it responds to harmless foreign substances as though they were pathogens. Sometimes it attacks the body’s own cells. Certain diseases can also attack and damage the immune system and interfere with its ability to defend the body. |
Although they differ vastly in hardness, pencil lead and diamonds both contain what element? | oxygen | graphite | hydrogen | carbon | Hardness helps determine how an element (especially a metal) might be used. Many elements are fairly soft (silver and gold, for example) while others (such as titanium, tungsten, and chromium) are much harder. Carbon is an interesting example of hardness. In graphite (the “lead” found in pencils) the carbon is very soft, while the carbon in a diamond is roughly seven times as hard. |
The majority of salamanders lack what organs, so respiration occurs through the skin or through external gills? | noses | throats | mouths | lungs | Modern Amphibians Amphibia comprises an estimated 6,770 extant species that inhabit tropical and temperate regions around the world. Amphibians can be divided into three clades: Urodela (“tailed-ones”), the salamanders; Anura (“tail-less ones”), the frogs; and Apoda (“legless ones”), the caecilians. Urodela: Salamanders Salamanders are amphibians that belong to the order Urodela. Living salamanders (Figure 29.16) include approximately 620 species, some of which are aquatic, other terrestrial, and some that live on land only as adults. Adult salamanders usually have a generalized tetrapod body plan with four limbs and a tail. They move by bending their bodies from side to side, called lateral undulation, in a fish-like manner while “walking” their arms and legs fore and aft. It is thought that their gait is similar to that used by early tetrapods. Respiration differs among different species. The majority of salamanders are lungless, and respiration occurs through the skin or through external gills. Some terrestrial salamanders have primitive lungs; a few species have both gills and lungs. Unlike frogs, virtually all salamanders rely on internal fertilization of the eggs. The only male amphibians that possess copulatory structures are the caecilians, so fertilization among salamanders typically involves an elaborate and often prolonged courtship. Such a courtship allows the successful transfer of sperm from male to female via a spermatophore. Development in many of the most highly evolved salamanders, which are fully terrestrial, occurs during a prolonged egg stage, with the eggs guarded by the mother. During this time, the gilled larval stage is found only within the egg capsule, with the gills being resorbed, and metamorphosis being completed, before hatching. Hatchlings thus resemble tiny adults. |
Crabs, lobsters, shrimp, krill, and woodlice are all? | arthropods | sponges | porifera | crustaceans | Crustaceans include crabs, lobsters, shrimp, krill, and woodlice. |
What makes water change to a different state? | gravity | pressure | time | temperature | The state the water is in depends upon the temperature. Each state (solid, liquid, and gas) has its own unique set of physical properties. |
What is a hydrocarbon in which there are only single covalent bonds? | fullerene | combined | proline | alkane | An alkane is a hydrocarbon in which there are only single covalent bonds. The simplest alkane is methane, with the molecular formula CH 4 . The carbon is the central atom and makes four single covalent bonds to hydrogen atoms. |
What is the measure of the amount of space occupied by an object? | growth | mass | liquid | volume | Volume Volume is the measure of the amount of space occupied by an object. The standard SI unit of volume is defined by the base unit of length (Figure 1.25). The standard volume is a cubic meter (m3), a cube with an edge length of exactly one meter. To dispense a cubic meter of water, we could build a cubic box with edge lengths of exactly one meter. This box would hold a cubic meter of water or any other substance. A more commonly used unit of volume is derived from the decimeter (0.1 m, or 10 cm). A cube with edge lengths of exactly one decimeter contains a volume of one cubic decimeter (dm3). A liter (L) is the more common name for the cubic decimeter. One liter is about 1.06 quarts. A cubic centimeter (cm3) is the volume of a cube with an edge length of exactly one centimeter. The abbreviation cc (for cubic centimeter) is often used by health professionals. A cubic centimeter is also called a milliliter (mL) and is 1/1000 of a liter. |
The energy that enters the chloroplasts as sunlight becomes stored as what type of energy in organic compounds? | defect energy | radiation energy | thermal energy | chemical energy | |
Whose rules are too simple to explain the inheritance of human height? | Darwin | Einstein | Pascal | mendel | Unlike Mendel's peas, people do not all fall into two categories: short or tall. Most people, in fact, are somewhere in between. Obviously, Mendel's rules are too simple to explain the inheritance of human height. |
The fertilized egg that sexually reproducing organisms begin life as is known as what? | infant | gamete | fetus | zygote | Introduction The individual sexually reproducing organism—including humans—begins life as a fertilized egg, or zygote. Trillions of cell divisions subsequently occur in a controlled manner to produce a complex, multicellular human. In other words, that original single cell was the ancestor of every other cell in the body. Once a human individual is fully grown, cell reproduction is still necessary to repair or regenerate tissues. For example, new blood and skin cells are constantly being produced. All multicellular organisms use cell division for growth, and in most cases, the maintenance and repair of cells and tissues. Single-celled organisms use cell division as their method of reproduction. |
People with red hair usually have what type of skin? | dry | dark | oily | light | 7. People with red hair usually have very light skin. What might be a genetic explanation for this observation?. |
What provides the shape of a cell? | cellulose | nucleus | cytoplasm | cytoskeleton | The cytoskeleton provides the shape of the cell. |
Competition between members of the same species is known as? | nuchal competition | interspecies competition | egregious competition | intraspecific competition | Intraspecific competition occurs between members of the same species. For example, two male birds of the same species might compete for mates in the same area. This type of competition is a basic factor in natural selection. It leads to the evolution of better adaptations within a species. |
One molecule of carbon dioxide consists of 1 atom of carbon and 2 atoms of what element? | nitrogen | methane | hydrogen | oxygen | A molecular formula of the compound carbon dioxide is CO 2 . One molecule of carbon dioxide consists of 1 atom of carbon and 2 atoms of oxygen. We can calculate the mass of one molecule of carbon dioxide by adding together the masses of 1 atom of carbon and 2 atoms of oxygen. |
What facilitates the diffusion of ions across a membrane? | passive transport | photon channels | ionic bonds | ion channels | |
What kind of fibers are used to transport telephone and television signals? | hair fibers | touch fibers | process fibers | optical fibers | Total internal reflection allows the light to travel down the optical fiber and not pass through the sides of the tube. The light continuously reflects from the inside of the tube and eventually comes out the end. Optical fibers make interesting lamps but they are also used to transport telephone and television signals. |
In what century was the microscope invented? | 15th | 20th | 16th | 17th | 7.2 History of cell knowledge The optical microscope was first invented in 17th century. Shortly thereafter scientists began to examine living and dead biological tissues in order to better understand the science of life. Some of the most relevant discovery milestones of the time period include: • The invention of the microscope11 , which allowed scientists for the first time to see biological cells • Robert Hooke12 in 1665 looked at cork under a microscope and described what he called cork "cells" • Anton van Leeuwenhoek13 called the single-celled organisms that he saw under the microscope "animalcules" • Matthias Jakob Schleiden14 , a botanist, in 1838 determined that all plants consist of cells • Theodor Schwann15 , a zoologist, in 1839 determined that all animals consist of cells • Rudolf Virchow16 proposed the theory that all cells arise from previously existing cells In 1838, the botanist Matthias Jakob Schleiden and the physiologist Theodor Schwann discovered that both plant cells and animal cells had nuclei. Based on their observations, the two scientists conceived of the hypothesis that all living things were composed of cells. In 1839, Schwann published 'Microscopic Investigations on the Accordance in the Structure and Growth of Plants and Animals', which contained the first statement of their joint cell theory. |
What do the hair cells in the cochlea release when they bend? | lipids | receptors | hormones | neurotransmitters | The oval window passes the vibrations to the cochlea . The cochlea is filled with liquid that moves when the vibrations pass through, like the waves in water when you drop a pebble into a pond. Tiny hair cells line the cochlea and bend when the liquid moves. When the hair cells bend, they release neurotransmitters. |
Receptor clustering happens when what binds to the receptors? | carbohydrates | enzymes | lipid molecules | fas molecules | |
What makes toenails and fingernails hard? | taurine | guanine | cellulose | keratin | Fingernails and toenails consist of specialized epidermal cells that are filled with keratin. The keratin makes them tough and hard, which is important for the functions they serve. Fingernails prevent injury by forming protective plates over the ends of the fingers. They also enhance sensation by acting as a counterforce to the sensitive fingertips when objects are handled. |
Producing sperm and secreting testosterone are the main functions of what system? | female reproductive system | pollination | endocrine system | male reproductive system | The main functions of the male reproductive system are to produce sperm and secrete testosterone. |
Biochemistry is the study of the chemistry of? | abiotic factors | the Earth | inorganic matter | living systems | The related field of biochemistry overlaps to some extent with organic chemistry. Biochemistry is the study of the chemistry of living systems. Many biochemical compounds are considered to be organic chemicals. Both of the molecules shown above are biochemical materials in terms of their use in the body, but organic chemicals in terms of their structure and chemical reactivity. |
Color, temperature, and solubility are examples of what type of property? | susceptible | severe | minimal | intensive | Color, temperature, and solubility are examples of intensive properties. |
What is the term for nutrients the body needs in relatively small amounts, including vitamins and minerals? | trace nutrients | minor nutrients | insignificant nutrients | micronutrients | Nutrients the body needs in relatively small amounts are called micronutrients . They include vitamins and minerals. Vitamins are organic compounds that are needed by the body to function properly. Several vitamins are described in Table below . Vitamins play many roles in good health, ranging from maintaining good vision to helping blood clot. Vitamin B12 is produced by bacteria in the large intestine. Vitamin D is synthesized by the skin when it is exposed to UV light. Most other vitamins must be obtained from foods like those listed in Table below . |
What do corals secrete that builds up to become a coral reef? | saliva | actuators | tentacles | exoskeletons | Many corals secrete an exoskeleton that builds up to become a coral reef. |
Solid balls of water and dust falling from the sky are known as? | rain | snow | golf balls | hail | |
What brain structure is important in recognizing and recalling emotions? | thalmus | pituitary | cerebral cortex | amygdala | |
Oils are liquid lipids that plants use for storage of what? | oxygen | fat | glucose | energy | In unsaturated fatty acids, there is at least one double bond between carbon atoms. As a result, some carbons are not bonded to as many hydrogen atoms as possible. Unsaturated fatty acids are found in oils. Oils are liquid lipids that plants use to store energy. |
Where do the majority of arthropods live? | in air | in hives | in water | on land | The majority of mollusks and annelids live in the water or inside hosts. Arthropods are invertebrates that include insects. The majority of arthropods live on land. |
Protein chains containing 10 or fewer amino acids are usually referred to as what? | carboxyl | polypeptides | protons | peptides | the conditions, amino acids can act as either acids or bases, which means that proteins act as buffers. The pH at which an amino acid exists as the zwitterion is called theisoelectric point (pI). The amino acids in a protein are linked together by peptide bonds. Protein chains containing 10 or fewer amino acids are usually referred to as peptides, with a prefix such as di- or tri- indicating the number of amino acids. Chains containing more than 50 amino acid units are referred to as proteins orpolypeptides. Proteins are classified globular or fibrous, depending on their structure and resulting solubility in water. Globular proteins are nearly spherical and are soluble in water; fibrous proteins have elongated or fibrous structures and are not soluble in water. Protein molecules can have as many as four levels of structure. The primary structure is the sequence of amino acids in the chain. The secondary structure is the arrangement of adjacent atoms in the peptide chain; the most common arrangements are α-helices or β-pleated sheets. The tertiary structureis the overall three-dimensional shape of the molecule that results from the way the chain bends and folds in on itself. Proteins that consist of more than one chain have quaternary structure, which is the way the multiple chains are packed together. Four types of intramolecular and intermolecular forces contribute to secondary, tertiary, and quaternary structure: (1) hydrogen bonding between an oxygen or a nitrogen atom and a hydrogen atom bound to an oxygen atom or a nitrogen atom, either on the same chain or on a neighboring chain; (2) ionic bondingbetween one positively charged side chain and one negatively charged side chain; (3) disulfide linkages between cysteine units; and (4) dispersion forcesbetween nonpolar side chains. Because of their complexity, protein molecules are delicate and easy to disrupt. Adenatured protein is one whose conformation has been changed, in a process called denaturation, so that it can no longer do its physiological job. A variety of conditions, such as heat, ultraviolet radiation, the addition of organic compounds, or changes in pH can denature a protein. Saylor URL: http://www. saylor. org/books. |
The primary site of carbohydrate digestion is in the? | stomach | large intestine | mouth | small intestine | The primary site of carbohydrate digestion is the small intestine. The secretion of αamylase in the small intestine converts any remaining starch molecules, as well as the dextrins, to maltose. Maltose is then cleaved into two glucose molecules by maltase. Disaccharides such as sucrose and lactose are not digested until they reach the small intestine, where they are acted on by sucrase and lactase, respectively. The major. |
A potential cause of extinction, competition between different species is called what? | mutualism | parasitism | intraspecific competition | interspecific competition | Competition between different species is called interspecific competition. It might lead to the less well-adapted species going extinct. Or it might lead to one or both species evolving specialized adaptations. For example, competing species might evolve adaptations that allow them to use different food sources. You can see an example in Figure below . |
Within the microsporangium, the microspore mother cell divides by meiosis to give rise to four microspores, each of which will ultimately form this? | ova | zygote | sperm cell | pollen grain | Within the microsporangium, the microspore mother cell divides by meiosis to give rise to four microspores, each of which will ultimately form a pollen grain (Figure 32.7). An inner layer of cells, known as the tapetum, provides nutrition to the developing microspores and contributes key components to the pollen wall. Mature pollen grains contain two cells: a generative cell and a pollen tube cell. The generative cell is contained within the larger pollen tube cell. Upon germination, the tube cell forms the pollen tube through which the generative cell migrates to enter the ovary. During its transit inside the pollen tube, the generative cell divides to form two male gametes (sperm cells). Upon maturity, the microsporangia burst, releasing the pollen grains from the anther. |
What is regulated by the reticular formation? | anxiousness | awkwardness | sleepiness | wakefulness | Wakefulness is regulated by the reticular formation, which is present in the. |
All living things are capable of what process whereby living things give rise to offspring? | differentiation | cell division | mitosis | reproduction | All living things are capable of reproduction, the process by which living things give rise to offspring. |
What is the common name of mixtures of hydrocarbons that formed over millions of years from the remains of dead organisms? | non-renewable fuel | fossil record | renewable resources | fossil fuels | Fossil fuels are mixtures of hydrocarbons that formed over millions of years from the remains of dead organisms. They include petroleum (commonly called oil), natural gas, and coal. Fossil fuels provide most of the energy used in the world today. They are burned in power plants to produce electrical energy, and they also fuel cars, heat homes, and supply energy for many other purposes. You can see examples of their use in Figure below . |
What branch of science is the study of the universe, not of cosmetics? | epistemology | theology | astronomy | cosmology | The study of the Universe is called cosmology . Cosmologists study the structure and changes in the present Universe. The Universe contains all of the star systems, galaxies, gas, and dust, plus all the matter and energy that exists now. Plus all that existed in the past, and all that will exist in the future. The Universe includes all of space and time. |
Which blood leaves the placenta through veins leading back to the fetus? | pelvic | immunity | molecular | fetal | |
Matter can be classified on the basis of how what interacts with it? | water | air | gravity | light | Matter can be classified on the basis of how light interacts with it. Matter may be transparent, translucent, or opaque. Each type of matter is illustrated in Figure below . |
What scale is used to succinctly communicate the acidity or basicity of a solution? | ions | Richter scale | solvent scale | ph | The pH scale is used to succinctly communicate the acidity or basicity of a solution. |
Hormones often regulate what through antagonistic functions? | breathing | hypothesis | consciousness | homeostasis | |
The potential of what can be used to measure the ph of a solution? | stimulation cell | electrodes cell | symbiotic cell | galvanic cell | Thus the potential of a galvanic cell can be used to measure the pH of a solution. Exercise Suppose you work for an environmental laboratory and you want to use an electrochemical method to measure the concentration of Pb2+ in groundwater. You construct a galvanic cell using a standard oxygen electrode in one compartment (E°cathode = 1.23 V). The other compartment contains a strip of lead in a sample of groundwater to which you have added sufficient acetic acid, a weak organic acid, to ensure electrical conductivity. The cell diagram is as follows”. |
What theory says atoms of matter are in constant random motion? | sound kinetic theory | the theory of relativity | modern residual theory | modern kinetic theory | A: The modern kinetic theory of matter is remarkably similar to Democritus’ ideas about the motion of atoms. According to this theory, atoms of matter are in constant random motion. This motion is greater in gases than in liquids, and it is greater in liquids than in solids. But even in solids, atoms are constantly vibrating in place. |
The laws of what field of science apply to galaxies and atoms, an indication of the underlying unity in the universe? | astronomy | anthropology | geology | physics | Figure 1.1 Galaxies are as immense as atoms are small. Yet the same laws of physics describe both, and all the rest of nature—an indication of the underlying unity in the universe. The laws of physics are surprisingly few in number, implying an underlying simplicity to nature’s apparent complexity. (credit: NASA, JPL-Caltech, P. Barmby, Harvard-Smithsonian Center for Astrophysics). |
What makes soil and rock particles move gradually down the slope during each thaw? | rain | heat | wind | gravity | Hot spots may also be active at plate boundaries. This is especially common at mid-ocean ridges. Iceland is formed by a hot spot along the Mid-Atlantic Ridge. |
What is the protist kingdom sometimes called as? | plant can kingdom | fossil can kingdom | flora can system | trash can kingdom | The protist kingdom is sometimes called the “trash can” kingdom. It includes all eukaryotes that don’t fit in one of the other three eukaryote kingdoms: Animalia, Plantae, or Fungi. There are thought to be between 60,000 and 200,000 protist species. Many have yet to be identified. The protist kingdom is very diverse, as shown in Figure below . |
The constant "c" can be specifically used to represent the (extremely fast) speed of what? | gravity | electricity | sound | light | n = cv , where v is the observed speed of light in the material. Since the speed of light is always less than only in a vacuum, the index of refraction is always greater than or equal to one. |
What are non-renewable sources of energy that produce environmental damage? | wind | crop fuels | sunlight | fossil fuels | Fossil fuels are non-renewable sources of energy that produce environmental damage. |
What causes cancer cells to avoid elimination and continue to multiply? | persistent cell division | continuous cell division | chronic cell division | uncontrolled cell division | When normal cells are damaged beyond repair, they are eliminated. The upper diagram depicts damaged cells being destroyed. Cancer cells avoid elimination and, because of uncontrolled cell division, continue to multiply in an unregulated manner. The lower diagram depicts damaged cells dividing in an uncontrolled fashion. |
Electronegativity is a qualitative measure of how much an atom attracts what in a covalent bond? | isotopes | neutrons | protons | electrons | Electronegativity is a qualitative measure of how much an atom attracts electrons in a covalent bond. |
Depending on how matter interacts with light, it can be classified as transparent, translucent, or what? | protective | reflective | reactive | opaque | Matter can be classified as transparent, translucent, or opaque depending on how it interacts with light. |
Kidneys, large intestine, liver, skin, and lungs comprise which system? | Lymphatic system | Muscular system | Digestive system | excretory system | Organs of excretion make up the excretory system. They include the kidneys, large intestine, liver, skin, and lungs. |
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