questions stringlengths 37 1.22k | reasoning stringlengths 0 3.56k ⌀ | answers stringlengths 4 138 |
|---|---|---|
Why do mangrove trees rise high above the water? which characteristic help them to do so?
Here are the choices:
A. no roots
B. stilt like roots
C. fat roots
D. heavy roots | Mangrove roots are like stilts, allowing mangrove trees to rise high above the water. The trunk and leaves are above water even at high tide. A bloodroot plant uses food stored over the winter to grow flowers in the early spring. | B: stilt like roots. |
What fertilizes an egg during sexual reproduction?
Here are the choices:
A. cytoplasm
B. mucus
C. sperm
D. gametes | Image copyright James Steidl, 2014. During sexual reproduction, a sperm fertilizes an egg . Used under license from Shutterstock. com. | C: sperm. |
How does the fungus benefit from the photosynthesizer?
Here are the choices:
A. supply of food
B. shade
C. protection from chemicals
D. supply of carbon dioxide | A lichen is an organism that results from a mutualistic relationship between a fungus and a photosynthetic organism. The other organism is usually a cyanobacterium or green alga. The fungus grows around the bacterial or algal cells. The fungus benefits from the constant supply of food produced by the photosynthesizer. The photosynthesizer benefits from the water and nutrients absorbed by the fungus. Figure below shows lichen growing on a rock. | A: supply of food. |
What is the name for unsaturated hydrocarbons that contain at least one double bond?
Here are the choices:
A. enzymes
B. acids
C. alkenes
D. lipids | Unsaturated hydrocarbons that contain at least one double bond are called alkenes . The name of a specific alkene always ends in – ene , with a prefix indicating the number of carbon atoms. Figure below shows the structural formula for the smallest alkene. It has just two carbon atoms and is named ethene. Ethene is produced by most fruits and vegetables. It speeds up ripening and also rotting. Figure below shows the effects of ethene on bananas. | C: alkenes. |
What is the term for a loop in which a product feeds back to control its own production?
Here are the choices:
A. Recondition Mechanism
B. feedback mechanism
C. load mechanism
D. Adaptive Mechanism | Hormones control many cell activities, so they are very important for homeostasis. But what controls the hormones themselves? Most hormones are regulated by feedback mechanisms. A feedback mechanism is a loop in which a product feeds back to control its own production. Most hormone feedback mechanisms involve negative feedback loops. Negative feedback keeps the concentration of a hormone within a narrow range. | B: feedback mechanism. |
During what period on earth was coal formed?
Here are the choices:
A. Neoproterozoic era
B. Neoproterozoic
C. Mesozoic
D. the carboniferous period | The Carboniferous Period : Next, during the Carboniferous Period (360–290 million years ago), widespread forests of huge plants left massive deposits of carbon that eventually turned to coal. The first amphibians evolved to move out of the water and colonize land, but they had to return to the water to reproduce. Soon after amphibians arose, the first reptiles evolved. They were the first animals that could reproduce on dry land. | D: the carboniferous period. |
What is the term for the visible part of the electromagnetic spectrum?
Here are the choices:
A. gravity
B. chroma
C. light
D. electricity | Earth is just a tiny speck in the Universe. Our planet is surrounded by lots of space. Light travels across empty space. Light is the visible part of the electromagnetic spectrum . Astronomers use the light and other energy that comes to us to gather information about the Universe. | C: light. |
Which vertebrates were the first with four limbs?
Here are the choices:
A. bony fishes
B. birds
C. reptiles
D. amphibians (or tetrapods) | Amphibians are the first true tetrapods, or vertebrates with four limbs. | D: amphibians (or tetrapods). |
How do plants support themselves above the ground to get light and oxygen?
Here are the choices:
A. symbiosis
B. stiff stems
C. flaccid stems
D. momentum | Heat and light are forms of energy. Other forms are chemical and electrical energy. Energy can’t be created or destroyed. It can change form. For example, a piece of wood has chemical energy stored in its molecules. When the wood burns, the chemical energy changes to heat and light energy. | B: stiff stems. |
What process starts with glucose and ends with two pyruvate molecules, a total of four atp molecules and two molecules of nadh?
Here are the choices:
A. photosynthesis
B. glycolysis
C. secretion
D. absorption | Outcomes of Glycolysis Glycolysis starts with glucose and ends with two pyruvate molecules, a total of four ATP molecules and two molecules of NADH. Two ATP molecules were used in the first half of the pathway to prepare the six-carbon ring for cleavage, so the cell has a net gain of two ATP molecules and 2 NADH molecules for its use. If the cell cannot catabolize the pyruvate molecules further, it will harvest only two ATP molecules from one molecule of glucose. Mature mammalian red blood cells are not capable of aerobic respiration—the process in which organisms convert energy in the presence of oxygen—and glycolysis is their sole source of ATP. If glycolysis is interrupted, these cells lose their ability to maintain their sodium-potassium pumps, and eventually, they die. The last step in glycolysis will not occur if pyruvate kinase, the enzyme that catalyzes the formation of pyruvate, is not available in sufficient quantities. In this situation, the entire glycolysis pathway will proceed, but only two ATP molecules will be made in the second half. Thus, pyruvate kinase is a rate-limiting enzyme for glycolysis. | B: glycolysis. |
What paired organs help regulate blood pressure through sodium ion and water retention and loss?
Here are the choices:
A. lungs
B. tissues
C. lymph nodes
D. kidneys | 25.10 The Urinary System and Homeostasis The effects of failure of parts of the urinary system may range from inconvenient (incontinence) to fatal (loss of filtration and many others). The kidneys catalyze the final reaction in the synthesis of active vitamin D that in turn helps regulate Ca++. The kidney hormone EPO stimulates erythrocyte development and promotes adequate O2 transport. The kidneys help regulate blood pressure through Na+ and water retention and loss. The kidneys work with the adrenal cortex, lungs, and liver in the renin–angiotensin–aldosterone system to regulate blood pressure. They regulate osmolarity of the blood by regulating both solutes and water. Three electrolytes are more closely regulated than others: Na+, Ca++, and K+. The kidneys share pH regulation with the lungs and plasma buffers, so that proteins can preserve their three-dimensional conformation and thus their function. | D: kidneys. |
What is the age-related disorder that causes the gradual loss of bone density and strength?
Here are the choices:
A. mitosis
B. fibrosis
C. osteoporosis
D. arthritis | Figure 7.22 Osteoporosis Osteoporosis is an age-related disorder that causes the gradual loss of bone density and strength. When the thoracic vertebrae are affected, there can be a gradual collapse of the vertebrae. This results in kyphosis, an excessive curvature of the thoracic region. | C: osteoporosis. |
What are microfilaments made out of?
Here are the choices:
A. two halophilic chains
B. two DNA chains
C. two actin chains
D. two microscopy chains | C: two actin chains. | |
Which bones are the large, curved bones that form the lateral and anterior aspects of the pelvis?
Here are the choices:
A. toe
B. hip
C. cranium
D. foot | Hip Bone The hip bone, or coxal bone, forms the pelvic girdle portion of the pelvis. The paired hip bones are the large, curved bones that form the lateral and anterior aspects of the pelvis. Each adult hip bone is formed by three separate bones that fuse together during the late teenage years. These bony components are the ilium, ischium, and pubis (Figure 8.13). These names are retained and used to define the three regions of the adult hip bone. | B: hip. |
What bifurcates into the right and left bronchi in the lungs?
Here are the choices:
A. aorta
B. neck
C. cornea
D. trachea | Figure 39.9 The trachea bifurcates into the right and left bronchi in the lungs. The right lung is made of three lobes and is larger. To accommodate the heart, the left lung is smaller and has only two lobes. | D: trachea. |
What is the spreading of white light into its full spectrum of wavelengths called?
Here are the choices:
A. condensation
B. dispersion
C. radiate
D. saturation | 25.5 Dispersion: The Rainbow and Prisms • The spreading of white light into its full spectrum of wavelengths is called dispersion. • Rainbows are produced by a combination of refraction and reflection and involve the dispersion of sunlight into a continuous distribution of colors. • Dispersion produces beautiful rainbows but also causes problems in certain optical systems. | B: dispersion. |
What type of fertilization usually occurs in aquatic environments where both eggs and sperm are released into the water?
Here are the choices:
A. external
B. static
C. material
D. Internal | External Fertilization External fertilization usually occurs in aquatic environments where both eggs and sperm are released into the water. After the sperm reaches the egg, fertilization takes place. Most external fertilization happens during the process of spawning where one or several females release their eggs and the male(s) release sperm in the same area, at the same time. The release. | A: external. |
What is the energy of motion called?
Here are the choices:
A. stasis
B. kinetic energy
C. harmonic energy
D. inertia | According to the kinetic theory, particles of matter are in constant motion. The energy of motion is called kinetic energy. | B: kinetic energy. |
Overharvesting is especially challenging for species with what type of habitat?
Here are the choices:
A. allowed
B. classified
C. restricted
D. tundra | C: restricted. | |
What is a representation of the valence electrons of an atom that uses dots around the symbol of the element?
Here are the choices:
A. right structure
B. watson structure
C. time structure
D. lewis structure | In almost all cases, chemical bonds are formed by interactions of valence electrons in atoms. To facilitate our understanding of how valence electrons interact, a simple way of representing those valence electrons would be useful. A Lewis electron dot diagram (or electron dot diagram or a Lewis diagram or a Lewis structure) is a representation of the valence electrons of an atom that uses dots around the symbol of the element. The number of dots equals the number of valence electrons in the atom. These dots are arranged to the right and left and above and below the symbol, with no more than two dots on a side. (It does not matter what order the positions are used. ) For example, the Lewis electron dot diagram for hydrogen is simply. | D: lewis structure. |
Massive quanta, like electrons, also act like macroscopic particles—something we expect, because they are the smallest what?
Here are the choices:
A. units of matter
B. battalions of matter
C. depth of matter
D. regiments of matter | 29.4 Photon Momentum Measuring Photon Momentum The quantum of EM radiation we call a photon has properties analogous to those of particles we can see, such as grains of sand. A photon interacts as a unit in collisions or when absorbed, rather than as an extensive wave. Massive quanta, like electrons, also act like macroscopic particles—something we expect, because they are the smallest units of matter. Particles carry momentum as well as energy. Despite photons having no mass, there has long been evidence that EM radiation carries momentum. (Maxwell and others who studied EM waves predicted that they would carry momentum. ) It is now a well-established fact that photons do have momentum. In fact, photon momentum is suggested by the photoelectric effect, where photons knock electrons out of a substance. Figure 29.17 shows macroscopic evidence of photon momentum. | A: units of matter. |
The simplest example of what type of 'organ system' is the gastrovascular cavity found in organisms with only one opening for the process?
Here are the choices:
A. nervous
B. digestive
C. cardiovascular
D. respiratory | Invertebrate Digestive Systems Animals have evolved different types of digestive systems to aid in the digestion of the different foods they consume. The simplest example is that of a gastrovascular cavity and is found in organisms with only one opening for digestion. Platyhelminthes (flatworms), Ctenophora (comb jellies), and Cnidaria (coral, jelly fish, and sea anemones) use this type of digestion. Gastrovascular cavities, as shown in Figure 34.5a, are typically a blind tube or cavity with only one opening, the “mouth”, which also serves as an “anus”. Ingested material enters the mouth and passes through a hollow, tubular cavity. Cells within the cavity secrete digestive enzymes that break down the food. The food particles are engulfed by the cells lining the gastrovascular cavity. The alimentary canal, shown in Figure 34.5b, is a more advanced system: it consists of one tube with a mouth at one end and an anus at the other. Earthworms are an example of an animal with an alimentary canal. Once the food is ingested through the mouth, it passes through the esophagus and is stored in an organ called the crop; then it passes into the gizzard where it is churned and digested. From the gizzard, the food passes through the intestine, the nutrients are absorbed, and the waste is eliminated as feces, called castings, through the anus. | B: digestive. |
Photographs of the heat emitted by an object are called what?
Here are the choices:
A. radio images
B. cosmic images
C. thermal images
D. variable images | C: thermal images. | |
Graphite is a form of elemental carbon what is another form?
Here are the choices:
A. magnite
B. iron
C. carbonite
D. diamond | Graphite and diamond are two forms of elemental carbon. Write the equilibrium equation between these two forms in two different ways. | D: diamond. |
If everything else stays the same in a system with a gas in it, and the gas gets warmer, what will happen to its pressure, generally?
Here are the choices:
A. it stays the same
B. it increases
C. it drops
D. it's eliminated | Why does the pressure of a gas increase as it gets warmer? Particles of a gas are constantly moving and bumping into things. The force of the collisions is measured by pressure. Pressure is the amount of force exerted on a given area, such as pounds of force per square inch. When gas particles heat up and gain energy, they move faster. This causes more collisions and greater pressure. Therefore, heating particles of gas in a closed space causes the pressure of the gas to increase. Explore the behavior of gas particles at different temperatures at the following URL. Change the temperature of the gas and watch what happens to its particles. | B: it increases. |
What term means a failure, insufficiency, or delay in the response of the immune system, which may be acquired or inherited?
Here are the choices:
A. vitamin deficiency
B. immunodeficiency
C. pathogenic
D. anemia | Immunodeficiency Immunodeficiency is a failure, insufficiency, or delay in the response of the immune system, which may be acquired or inherited. Immunodeficiency can allow pathogens or tumor cells to gain a foothold and replicate or proliferate to high enough levels so that the immune system becomes overwhelmed. Immunodeficiency can be acquired as a result of infection with certain pathogens that attack the cells of the immune system itself (such as HIV), chemical exposure (including certain medical treatments such as chemotherapy), malnutrition, or extreme stress. For instance, radiation exposure can destroy populations of lymphocytes and elevate an individual’s susceptibility to infections and cancer. Rarely, primary immunodeficiencies that are present from birth may also occur. For example, severe combined immunodeficiency disease (SCID) is a condition in which children are born without functioning B or T cells. | B: immunodeficiency. |
The mature pollen grain is composed of two cells: the pollen tube cell and which other cell?
Here are the choices:
A. glial cell
B. generative cell
C. photosynthesis cell
D. ova | Figure 32.7 Pollen develops from the microspore mother cells. The mature pollen grain is composed of two cells: the pollen tube cell and the generative cell, which is inside the tube cell. The pollen grain has two coverings: an inner layer (intine) and an outer layer (exine). The inset scanning electron micrograph shows Arabidopsis lyrata pollen grains. (credit “pollen micrograph”: modification of work by Robert R. Wise; scale-bar data from Matt Russell). | B: generative cell. |
The neck of the uterus, called the cervix, opens into what?
Here are the choices:
A. bladder
B. vagina
C. retina
D. testicle | B: vagina. | |
Where does the small intestine begin?
Here are the choices:
A. mouth
B. colon
C. stomach
D. spleen | The small intestine a is narrow tube that starts at the stomach and ends at the large intestine ( Figure above ). In adults, the small intestine is about 23 feet long. Chemical digestion takes place in the first part of the small intestine. Many enzymes and other chemicals are secreted here. The small intestine is also where most nutrients are absorbed into the blood. The later sections of the small intestines are covered with tiny projections called villi ( Figure below ). Villi contain very tiny blood vessels. Nutrients are absorbed into the blood through these tiny vessels. There are millions of villi, so, altogether, there is a very large area for absorption to take place. In fact, villi make the inner surface area of the small intestine 1,000 times larger than it would be without them. The entire inner surface area of the small intestine is about as big as a basketball court!. | C: stomach. |
What type of shape does a pelvic inlet have?
Here are the choices:
A. cylindrical
B. oval shape
C. cubic
D. conical | Pelvic inlet has a round or oval shape. | B: oval shape. |
Which stage of life is typically easier for learning multiple languages?
Here are the choices:
A. adulthood
B. infancy
C. childhood
D. adolescenc | C: childhood. | |
What is released from the body during ejaculation?
Here are the choices:
A. sperm
B. urine
C. saliva
D. blood | Sperm are released from the body during ejaculation . Ejaculation occurs when muscle contractions propel sperm from the epididymis. The sperm are forced through the ducts and out of the body through the urethra. As sperm travel through the ducts, they mix with fluids from the glands to form semen. Hundreds of millions of sperm are released with each ejaculation. | A: sperm. |
An organism's unique role in the ecosystem is called its what?
Here are the choices:
A. adaptation
B. focus
C. purpose
D. niche | Are you on the basketball team? Are you a cheerleader? Do you play an instrument in the band? Your niche would be your role or place in the school. Organisms also each have their own niche in the ecosystem. Is an organism a producer or a consumer? How does the organism interact with other organisms? Is the organism involved in any symbiotic relationships?. | D: niche. |
With the exception of water, what accounts for more mass than any other component of living organisms?
Here are the choices:
A. fats
B. hormones
C. proteins
D. nervous tissue | 9.4 | Translation By the end of this section, you will be able to: • Describe the different steps in protein synthesis • Discuss the role of ribosomes in protein synthesis • Describe the genetic code and how the nucleotide sequence determines the amino acid and the protein sequence The synthesis of proteins is one of a cell’s most energy-consuming metabolic processes. In turn, proteins account for more mass than any other component of living organisms (with the exception of water), and proteins perform a wide variety of the functions of a cell. The process of translation, or protein synthesis, involves decoding an mRNA message into a polypeptide product. Amino acids are covalently strung together in lengths ranging from approximately 50 amino acids to more than 1,000. | C: proteins. |
Atoms are combined, separated, or rearranged during what?
Here are the choices:
A. radiation
B. chemical reactions
C. physical reactions
D. spontaneous mutation | In chemical reactions, atoms are combined, separated, or rearranged. | B: chemical reactions. |
How many electrons does lithium have?
Here are the choices:
A. four
B. two
C. seven
D. three | D: three. | |
What is considered the center of the solar system?
Here are the choices:
A. nebulla
B. earth
C. heat
D. sun | Today we know that we have eight planets, five dwarf planets, over 165 moons, and many, many asteroids and other small objects in our solar system. We also know that the Sun is not the center of the universe. But it is the center of the solar system. | D: sun. |
What is the purpose of your body's first line of defense?
Here are the choices:
A. to keep out pathogens
B. reject foreign bodies
C. fight or flight
D. heal wounds | Your body’s first line of defense is like a castle’s moat and walls. It keeps most pathogens out of your body. The first line of defense includes physical, chemical, and biological barriers. | A: to keep out pathogens. |
What functions as a framework that reinforces the shape of the leaf?
Here are the choices:
A. the vascular structure
B. the stylised structure
C. the central structure
D. the normal structure | A: the vascular structure. | |
Like quarks, gluons may be confined to systems having a total color of what?
Here are the choices:
A. red
B. white
C. blue
D. yellow | Gluons ( g ) are the proposed carrier particles for the strong nuclear force, although they are not directly observed. Like quarks, gluons may be confined to systems having a total color of white. Less is known about gluons than the fact that they are the carriers of the weak and certainly of the electromagnetic force. QCD theory calls for eight gluons, all massless and all spin 1. Six of the gluons carry a color and an anticolor, while two do not carry color, as illustrated in Figure 33.22(a). There is indirect evidence of the existence of gluons in nucleons. When high-energy electrons are scattered from nucleons and evidence of quarks is seen, the momenta of the quarks are smaller than they would be if there were no gluons. That means that the gluons carrying force between quarks also carry some momentum, inferred by the already indirect quark momentum measurements. At any rate, the gluons carry color charge and can change the colors of quarks when exchanged, as seen in Figure 33.22(b). In the figure, a red down quark interacts with a green strange quark by sending it a gluon. That gluon carries red away from the down. | B: white. |
The ozone layer protects the earth from what?
Here are the choices:
A. light waves
B. uv radiation
C. radio waves
D. pollution | Plants maintain the atmosphere. They produce oxygen and absorb carbon dioxide during photosynthesis. Oxygen is essential for cellular respiration for all aerobic organisms. It also maintains the ozone layer that helps protect Earth’s life from damaging UV radiation. Removal of carbon dioxide from the atmosphere reduces the greenhouse effect and global warming. | B: uv radiation. |
What type of learning is based on past experience and reasoning?
Here are the choices:
A. reflect
B. insight
C. theory
D. experiment | Insight learning , which is based on past experience and reasoning, is a hallmark of the human animal. Humans have used insight learning to solve problems ranging from starting a fire to traveling to the moon. It usually involves coming up with new ways to solve problems. Insight learning generally happens quickly. An animal has a sudden flash of insight. Insight learning requires relatively great intelligence. Human beings use insight learning more than any other species. They have used their intelligence to solve problems ranging from inventing the wheel to flying rockets into space. | B: insight. |
What type of energy from a warm cola results in melting when it is transferred to the much colder ice?
Here are the choices:
A. protective energy
B. thermal energy
C. cyclic energy
D. gaseous energy | How do you cool down a glass of room-temperature cola? You probably add ice cubes to it, as in the Figure below . You might think that the ice cools down the cola, but in fact, it works the other way around. The warm cola heats up the ice. Thermal energy from the warm cola is transferred to the much colder ice, causing it to melt. The cola loses thermal energy in the process, so its temperature falls. | B: thermal energy. |
What is the term for a connection between a neuron and its target cell?
Here are the choices:
A. dendrite
B. impulse
C. synapse
D. axon | Figure 12.27 The Synapse The synapse is a connection between a neuron and its target cell (which is not necessarily a neuron). The presynaptic element is the synaptic end bulb of the axon where Ca2+ enters the bulb to cause vesicle fusion and neurotransmitter release. The neurotransmitter diffuses across the synaptic cleft to bind to its receptor. The neurotransmitter is cleared from the synapse either by enzymatic degradation, neuronal reuptake, or glial reuptake. | C: synapse. |
What does the slope of a position-time graph represent?
Here are the choices:
A. trajectory
B. velocity
C. direction
D. acceleration | The slope of a position-time graph represents velocity. The steeper the slope is, the faster the motion is changing. | B: velocity. |
What effect causes an object to appear to have a change of motion?
Here are the choices:
A. centrifugal effect
B. coriolis effect
C. resonant effect
D. momentum effect | Coriolis is an effect rather than a force. Coriolis does not force a motion. An object appears to have a change of motion due to the Coriolis effect. | B: coriolis effect. |
A carcinogen is nything in the environment that can cause what disease?
Here are the choices:
A. cancer
B. diabetes
C. glaucoma
D. alzheimers | Some mutations that lead to cancer may be inherited. However, most of the mutations are caused by environmental factors. Anything in the environment that can cause cancer is called a carcinogen. Common carcinogens include certain chemicals and some types of radiation. | A: cancer. |
What does the blue color of the pulmonary arteries reflect?
Here are the choices:
A. they are done
B. they are deoxygenated
C. they are lost
D. they are oxygenated | Figure 16.12 The arteries of the body, indicated in red, start at the aortic arch and branch to supply the organs and muscles of the body with oxygenated blood. The veins of the body, indicated in blue, return blood to the heart. The pulmonary arteries are blue to reflect the fact that they are deoxygenated, and the pulmonary veins are red to reflect that they are oxygenated. (credit: modification of work by Mariana Ruiz Villareal). | B: they are deoxygenated. |
The trade winds are nearest what?
Here are the choices:
A. boundary plates
B. equator
C. poles
D. inland | The wind belts have names. The Trade Winds are nearest the equator. The next belt is the westerlies. Finally are the polar easterlies. The names are the same in both hemispheres. | B: equator. |
Digestion of polysaccharides and disaccharides in the small intestine produces glucose and other?
Here are the choices:
A. protein
B. monosaccharides
C. fat
D. nitrates | Digestion of polysaccharides and disaccharides in the small intestine produces glucose and other monosaccharides. | B: monosaccharides. |
What is the term for the smallest blood vessels?
Here are the choices:
A. arteries
B. muscles
C. capillaries
D. Aortas | Capillaries are the smallest type of blood vessels. They connect the smallest arteries (arterioles) and veins (venules). Exchange of substances between cells and the blood takes place across the walls of capillaries, which may be only one cell thick. | C: capillaries. |
In what type of body of water is most of the earth's water located?
Here are the choices:
A. streams
B. oceans
C. seas
D. rivers | Most of Earth’s water is salt water in the oceans. As seen below, only 3 percent of Earth’s water is fresh ( Figure below ). Freshwater is water that contains little or no dissolved salt. Most freshwater is frozen in ice caps and glaciers. Glaciers cover the peaks of some tall mountains. For example, the Cascades Mountains in North America and the Alps Mountains in Europe are capped with ice. Ice caps cover vast areas of Antarctica and Greenland. Chunks of ice frequently break off ice caps. They form icebergs that float in the oceans. | B: oceans. |
What is one problem with current methods of aluminum production?
Here are the choices:
A. recycling is cheap
B. environmental contaminants
C. food shortages
D. competition | One problem with current methods of aluminum production is the generation of environmental contaminants. Hydrogen fluoride gas is an extremely corrosive and toxic byproduct that must be trapped and neutralized. Other fluorides and metals contaminants can also pollute water, soil, and air if not carefully managed. | B: environmental contaminants. |
What makes the earth habitable for humans?
Here are the choices:
A. carbonate of water
B. availability of water
C. aridity of water
D. abundance of water | D: abundance of water. | |
Which kind of flowers carry both male and female floral organs?
Here are the choices:
A. creating flowers
B. Upward Flowers
C. perfect flowers
D. stunning flowers | Figure 14.25 This image depicts the structure of a perfect and complete flower. Perfect flowers carry both male and female floral organs. (credit: modification of work by Mariana Ruiz Villareal). | C: perfect flowers. |
Historically, certain bacteriophages have also been used as cloning vectors for making what?
Here are the choices:
A. ultraviolet libraries
B. specific libraries
C. diverse libraries
D. genomic libraries | D: genomic libraries. | |
An allele is an alternative form of what structure?
Here are the choices:
A. enzyme
B. protein
C. amino acid
D. gene | You have learned that an allele is an alternative form of a gene. Most, if not all genes have alternative forms causing the resulting protein to function slightly differently. But are there alleles that cause proteins to function dramatically differently or not function at all? A mutation is a change in the DNA or RNA sequence, and many mutations result in new alleles. Some mutations have no effect on the protein, whereas others are either beneficial or harmful. In fact, evolution could not take place without the genetic variation that results from beneficial mutations. In humans, harmful mutations can result in genetic diseases. There are also chromosomal mutations, large changes with dramatic effects. See Mutations are changes in genetic information at http://www. dnaftb. org/27/animation. html for a description of the early work on mutations. | D: gene. |
All photosynthetic organisms contain a pigment called what?
Here are the choices:
A. chlorophyll
B. sodium
C. Fiber
D. carbonate | Understanding Pigments Different kinds of pigments exist, and each absorbs only certain wavelengths (colors) of visible light. Pigments reflect the color of the wavelengths that they cannot absorb. All photosynthetic organisms contain a pigment called chlorophyll a, which humans see as the common green color associated with plants. Chlorophyll a absorbs wavelengths from either end of the visible spectrum (blue and red), but not from green. Because green is reflected, chlorophyll appears green. Other pigment types include chlorophyll b (which absorbs blue and red-orange light) and the carotenoids. Each type of pigment can be identified by the specific pattern of wavelengths it absorbs from visible light, which is its absorption spectrum. Many photosynthetic organisms have a mixture of pigments; between them, the organism can absorb energy from a wider range of visible-light wavelengths. Not all photosynthetic organisms have full access to sunlight. Some organisms grow underwater where light intensity decreases with depth, and certain wavelengths are absorbed by the water. Other organisms grow in competition for light. Plants on the rainforest floor must be able to absorb any bit of light that comes through, because the taller trees block most of the sunlight (Figure 5.11). | A: chlorophyll. |
Mammals may either be herbivores, omnivores or what else?
Here are the choices:
A. polyvores
B. carnivores
C. herbivores
D. neither | Mammals may be herbivores, carnivores, or omnivores. They have four types of teeth, so they can eat a wide range of foods. | C: herbivores. |
What phenomenon sometimes causes harmful alleles to become fixed?
Here are the choices:
A. genetic drift
B. competition
C. spontaneous mutation
D. natural selection | A: genetic drift. | |
How do you determine the atomic weight of an element?
Here are the choices:
A. add up protons and neutrons
B. subtract protons from electrons
C. divide protons and neutrons
D. multiply protons and neutrons | The atomic weight of an element is a weighted average of its isotopes. | A: add up protons and neutrons. |
Sodium and chlorine combine to make what?
Here are the choices:
A. salt
B. gold
C. iron
D. seawater | Sodium is a highly reactive metal, and chlorine is a poisonous gas (see Figure below ). The compound they synthesize has very different properties. It is table salt, which is neither reactive nor poisonous. In fact, salt is a necessary component of the human diet. | A: salt. |
What can bacterial stis be cured with?
Here are the choices:
A. antibiotics
B. antiviral drugs
C. pesticides
D. antioxidants | Most STIs are caused by bacteria or viruses. Several of them are described below. Bacterial STIs can be cured with antibiotics. Viral STIs cannot be cured. Once you are infected with a viral STI, you are likely to be infected for life. | A: antibiotics. |
What do bees do for flowering plants?
Here are the choices:
A. feed
B. pollinate
C. eat
D. create | Thomas Quine (Flickr:quinet). Bees are important pollinators of flowering plants . CC BY 2.0. | B: pollinate. |
Where do streams often start?
Here are the choices:
A. plains
B. valleys
C. mountains
D. oceans | Streams often start in mountains, where the land is very steep. You can see an example in Figure below . A mountain stream flows very quickly because of the steep slope. This causes a lot of erosion and very little deposition. The rapidly falling water digs down into the stream bed and makes it deeper. It carves a narrow, V-shaped channel. | C: mountains. |
Deletions remove one or more what from the dna?
Here are the choices:
A. exons
B. codons
C. nucleotides
D. genes | Similar to chromosomal alteration mutations, deletion or insertion mutations add or remove genetic information. Small deletions or insertions in the DNA will alter the reading frame. Deletions remove one or more nucleotides from the DNA, whereas insertions add one or more nucleotides into the DNA. These mutations in the coding region of a gene may also alter the splicing of the mRNA, known as a splice site mutation . Mutations which alter the reading frame are known as frameshift mutations . Splice site mutations and frameshift mutations both can dramatically change the mRNA, altering the final protein product. | C: nucleotides. |
For geneticists, the findings of what massive undertaking are significant in determining disease-causing alleles?
Here are the choices:
A. human organisms project
B. Visible Human Project
C. human genome project
D. human produce project | Understanding and curing genetic diseases is the ultimate goal of human geneticists. As discussed in the Human Genetics: Diagnosis and Treatment (Advanced) concept, gene therapy is the insertion of a new gene into an individual’s cells and tissues to treat a disease, replacing a mutant disease-causing allele with a normal, non-mutant allele. Of course, the findings of the Human Genome Project are significant in determining the disease-causing alleles. Geneticists must know which are mutant alleles and which are non-mutant or "normal" alleles. They must also be able to identify alleles that are not just associated with a particular disease phenotype, but cause a disease phenotype. And of course, scientists must develop and test the technology to replace mutant alleles. | C: human genome project. |
Does deforestation increase or decrease carbon dioxide levels around the world?
Here are the choices:
A. increase
B. accelerate
C. decrease
D. eliminate | Jami Dwyer. Deforestation creates significant increases in carbon dioxide levels around the world . Public Domain. | A: increase. |
Which material used in oxyacetylene torches helps cut and weld metals?
Here are the choices:
A. acetylene
B. sulfur
C. dioxide
D. carbon | Note Acetylene is used in oxyacetylene torches for cutting and welding metals. The flame from such a torch can be very hot. Most acetylene, however, is converted to chemical intermediates that are used to make vinyl and acrylic plastics, fibers, resins, and a variety of other products. | A: acetylene. |
Peroxisomes perform a couple of different functions, including lipid metabolism and chemical detoxification. in contrast to the digestive enzymes found in lysosomes, the enzymes within peroxisomes serve to transfer hydrogen atoms from various molecules to oxygen, producing what?
Here are the choices:
A. water
B. hydrogen
C. hydrogen peroxide
D. calcium | Peroxisomes Like lysosomes, a peroxisome is a membrane-bound cellular organelle that contains mostly enzymes (Figure 3.17). Peroxisomes perform a couple of different functions, including lipid metabolism and chemical detoxification. In contrast to the digestive enzymes found in lysosomes, the enzymes within peroxisomes serve to transfer hydrogen atoms from various molecules to oxygen, producing hydrogen peroxide (H2O2). In this way, peroxisomes neutralize poisons such as alcohol. In order to appreciate the importance of peroxisomes, it is necessary to understand the concept of reactive oxygen species. | C: hydrogen peroxide. |
Ethylene, gibberellins, cytokinins, absciscic acid, and auxins are examples of what?
Here are the choices:
A. animal hormones
B. animal proteins
C. insect hormones
D. plant hormones | Plant hormones include ethylene, gibberellins, cytokinins, absciscic acid, and auxins. | D: plant hormones. |
What are some uses of chlorine gas?
Here are the choices:
A. cleaning, disinfecting and in swimming pools
B. washing hands
C. rooting plant cuttings
D. fueling airplanes | You may be able to avoid some of the health effects of outdoor air pollution by staying indoors on high-pollution days. However, some indoor air is just as polluted as outdoor air. | A: cleaning, disinfecting and in swimming pools. |
Designed to exchange materials, what spongy structure consists of membranes and blood vessels from both mother and embryo?
Here are the choices:
A. endometrium
B. placenta
C. uterus
D. umbilicus | The placenta is a spongy structure. It consists of membranes and blood vessels from both mother and embryo (see Figure below ). The placenta passes oxygen, nutrients, and other useful substances from the mother to the fetus. It also passes carbon dioxide and other wastes from the fetus to the mother. The placenta lets blood from the fetus and mother exchange substances without actually mixing. Thus, it protects the fetus from being attacked by the mother’s immune system as a “foreign parasite. ”. | B: placenta. |
Even though tellurium does indeed have a greater average atomic mass than iodine, it is properly placed before iodine in the?
Here are the choices:
A. phases table
B. periodic table
C. theory table
D. cycles table | When ordered by atomic number, the discrepancies within Mendeleev’s table disappeared. Tellurium has an atomic number of 52, while iodine has an atomic number of 53. Even though tellurium does indeed have a greater average atomic mass than iodine, it is properly placed before iodine in the periodic table. Mendeleev and Moseley are credited with formulating the modern periodic law , which states that when elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties. We will discuss some of these chemical and physical properties later on in this chapter. The result is the periodic table as we know it today. | B: periodic table. |
In a fullerene, what atoms are bonded to three other atoms in a soccer ball pattern?
Here are the choices:
A. hydrogen
B. oxygen
C. positive
D. carbon | In a fullerene, carbon atoms are bonded to three other atoms in a soccer ball pattern. The bonds are weak, so fullerenes can dissolve and form solutions. | D: carbon. |
What do you call the light particles that travel through the radiative zone?
Here are the choices:
A. photons
B. electrons
C. ions
D. neutrons | The radiative zone is the next layer out. It has a temperature of about 4 million degrees C. Energy from the core travels through the radiative zone. The rate the energy travels is extremely slow. Light particles, called photons, can only travel a few millimeters before they hit another particle. The particles are absorbed and then released again. It may take 50 million years for a photon to travel all the way through the radiative zone. | A: photons. |
What is a mixture of potassium nitrate, sulfur, and charcoal?
Here are the choices:
A. gunpowder
B. TNT
C. gasoline
D. cyanide | Nitrates, salts of nitric acid, form when metals, oxides, hydroxides, or carbonates react with nitric acid. Most nitrates are soluble in water; indeed, one of the significant uses of nitric acid is to prepare soluble metal nitrates. Nitric acid finds extensive use in the laboratory and in chemical industries as a strong acid and strong oxidizing agent. It is important in the manufacture of explosives, dyes, plastics, and drugs. Salts of nitric acid (nitrates) are valuable as fertilizers. Gunpowder is a mixture of potassium nitrate, sulfur, and charcoal. The reaction of N2O3 with water gives a pale blue solution of nitrous acid, HNO2. However, HNO2 (shown in Figure 18.51) is easier to prepare by the addition of an acid to a solution of nitrite; nitrous acid is a weak acid, so the nitrite ion is basic in aqueous solution: NO 2 −(aq) + H 3 O +(aq) ⟶ HNO 2(aq) + H 2 O(l) Nitrous acid is very unstable and exists only in solution. It disproportionates slowly at room temperature (rapidly when heated) into nitric acid and nitric oxide. Nitrous acid is an active oxidizing agent with strong reducing agents, and strong oxidizing agents oxidize it to nitric acid. | A: gunpowder. |
Opportunistic diseases are usually the direct cause of death of people with what disease?
Here are the choices:
A. parkinson
B. heart
C. liver
D. aids | boundary between air masses that is stalled in one place. | D: aids. |
What is the name of an uncharged particle whose weight is nearly equal to that of a proton?
Here are the choices:
A. electron
B. proton
C. a nuclei
D. a neutron | neutron : An uncharged particle with a mass nearly equal to that of the proton. Neutrons can be found in the nucleus of the atom. | D: a neutron. |
The chemical symbol of which ion is written first in ionic compounds?
Here are the choices:
A. positive metal ion
B. last ion
C. good metal ion
D. negative ion | Ionic compounds are compounds in which positive metal ions and negative nonmetal ions are joined by ionic bonds. In these compounds, the chemical symbol for the positive metal ion is written first, followed by the symbol for the negative nonmetal ion. The video at the following URL gives a fuller explanation of ionic compounds and their formulas: http://www. youtube. com/watch?v=vscoYh6m46M . | A: positive metal ion. |
What is the opposite of rarefaction zones, where air molecules in waves are loosely packed?
Here are the choices:
A. pressure wave
B. measurements zones
C. compression zones
D. molecules zones | Longitudinal waves, like sound waves, have compression and rarefaction zones. The compression zones are where, for example in a sound wave traveling through air, the air molecules are densely packed. The rarefaction zones are areas where the air molecules are loosely packed, like a vacuum zone. Us teachers will often draw longitudinal waves as transverse waves, but remember the difference. | C: compression zones. |
What organs secrete hormones that help maintain homeostasis?
Here are the choices:
A. the digestion organs
B. the gonads
C. the lungs
D. the kidneys | The kidneys also secrete hormones that help maintain homeostasis. For example, they produce a hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete a hormone that regulates blood pressure and keeps it in a normal range. | D: the kidneys. |
The nuclear envelope is a double-layered plasma membrane like the cell membrane, although without what?
Here are the choices:
A. nucleic acids
B. cell walls
C. membrane proteins
D. cytoplasm | Amoebozoa The amoebozoans characteristically exhibit pseudopodia that extend like tubes or flat lobes, rather than the hair-like pseudopodia of rhizarian amoeba (Figure 23.26). The Amoebozoa include several groups of unicellular amoeba-like organisms that are free-living or parasites. | C: membrane proteins. |
What is another name for a radioactive isotope?
Here are the choices:
A. xerophyte
B. nono particle
C. radiostope
D. kilocalorie | A radioactive isotope, or radioisotope, has atoms with unstable nuclei. The unstable nuclei naturally decay, or break down, by losing energy and particles of matter to become more stable. If they gain or lose protons as they decay, they become different elements. Over time, as the nuclei continue to decay, less and less of the original radioisotope remains. | C: radiostope. |
Dietary proteins are broken down into amino acids during what process?
Here are the choices:
A. filtration
B. photosynthesis
C. digestion
D. accumulation | Proteins in the diet are necessary for life. Dietary proteins are broken down into their component amino acids when food is digested. Cells can then use the components to build new proteins. Humans are able to synthesize all but eight of the twenty common amino acids. These eight amino acids, called essential amino acids , must be consumed in foods. Like dietary carbohydrates and lipids, dietary proteins can also be broken down to provide cells with energy. | C: digestion. |
Some gametophytes develop underground and form mycorrhizal associations with what?
Here are the choices:
A. fungi
B. plants
C. protists
D. animals | Lycophytes follow the pattern of alternation of generations seen in the bryophytes, except that the sporophyte is the major stage of the lifecycle. The gametophytes do not depend on the sporophyte for nutrients. Some gametophytes develop underground and form mycorrhizal associations with fungi. In club mosses, the sporophyte gives rise to sporophylls arranged in strobili, cone-like structures that give the class its name. Lycophytes can be homosporous or heterosporous. | A: fungi. |
What is the nervous tissue in the brain and in the rest of the nervous system made up of?
Here are the choices:
A. plastic
B. electrons
C. neurons
D. ions | Nervous tissue is made up of neurons , or nerve cells, that carry electrical messages. Nervous tissue makes up the brain and the nerves that connect the brain to all parts of the body. | C: neurons. |
How do planets usually rotate to their orbital planes?
Here are the choices:
A. nearly perpendicular
B. chaotic
C. randomly
D. exactly perpendicular | The axes of rotation of the planets are mostly nearly perpendicular to the orbital plane. | A: nearly perpendicular. |
What are algae that live in colonies of hundreds of cells called?
Here are the choices:
A. euglenids
B. rhodophyta
C. volvox
D. chlorophyta | Some single-celled organisms, such as algae, live in colonies. A colony is an organized structure composed of many cells, like the Volvox sphere in Figure below . Volvox are algae that live in colonies of hundreds of cells. All of the cells in the colony live and work cooperatively. For example, they can coordinate the movement of their flagella, allowing them to swim together through the water as though they were part of a single organism. | C: volvox. |
Irrigation can waste a lot of what natural resource?
Here are the choices:
A. money
B. fertilizer
C. habitat
D. water | Irrigation can waste a lot of water. The type of irrigation shown in Figure below is the most wasteful. The water is sprayed into the air and then falls to the ground. But much of the water never reaches the crops. Instead, it evaporates in the air or runs off the fields. Irrigation water may cause other problems. The water may dissolve agricultural chemicals such as pesticides. When the water soaks into the ground, the dissolved chemicals do, too. They may enter groundwater or run off into rivers or lakes. Salts in irrigation water can also collect in the soil. The soil may get too salty for plants to grow. | D: water. |
What drives puberty in male humans?
Here are the choices:
A. methane
B. testosterone
C. bloodstream
D. estrogen | Another obvious change that occurs during puberty is rapid growth. This is called the adolescent growth spurt . In boys, it is controlled by testosterone. The rate of growth usually starts to increase relatively early in puberty. At its peak rate, growth in height is about 10 centimeters (almost 4 inches) per year in the average male. Growth generally remains rapid for several years. Growth and development of muscles occur toward the end of the growth spurt in height. Muscles may continue to develop and gain strength after growth in height is finished. | B: testosterone. |
What is our largest source of energy?
Here are the choices:
A. coal
B. methane
C. wind
D. iron | Coal is our largest source of energy for producing electricity. | A: coal. |
Helium-3 is produced by beta decay of a certain what?
Here are the choices:
A. electron
B. particle
C. nuclide
D. quark | helium-3 is produced by beta decay of a certain nuclide. | C: nuclide. |
What do animals require to grow and develop?
Here are the choices:
A. carbon dioxide
B. sunlight
C. food
D. sucrose | 15.1 | Features of the Animal Kingdom By the end of this section, you will be able to: • List the features that distinguish the animal kingdom from other kingdoms • Explain the processes of animal reproduction and embryonic development • Describe the hierarchy of basic animal classification • Compare and contrast the embryonic development of protostomes and deuterostomes Even though members of the animal kingdom are incredibly diverse, animals share common features that distinguish them from organisms in other kingdoms. All animals are eukaryotic, multicellular organisms, and almost all animals have specialized tissues. Most animals are motile, at least during certain life stages. Animals require a source of food to grow and develop. All animals are heterotrophic, ingesting living or dead organic matter. This form of obtaining energy distinguishes them from autotrophic organisms, such as most plants, which make their own nutrients through photosynthesis and from fungi that digest their food externally. Animals may be carnivores, herbivores, omnivores, or parasites (Figure 15.2). Most animals reproduce sexually: The offspring pass through a series of developmental stages that establish a determined body plan, unlike plants, for example, in which the exact shape of the body is indeterminate. The body plan refers to the shape of an animal. | C: food. |
What term is used to describe the process by which organisms give rise to offspring?
Here are the choices:
A. reproduction
B. osmosis
C. variation
D. photosynthesis | A: reproduction. | |
What are the nonliving matter that living things need called?
Here are the choices:
A. elements
B. acids
C. nutrients
D. fluids | Living things need nonliving matter as well as energy. What do you think matter is used for? One thing is to build bodies. They also need it to carry out the processes of life. Any nonliving matter that living things need is called a nutrient . Carbon and nitrogen are examples of nutrients. Unlike energy, matter is recycled in ecosystems. You can see how in Figure below . | C: nutrients. |
What term is used to express the measurement of how high land is above sea level?
Here are the choices:
A. elevation
B. latitude
C. knots
D. distance | Elevation measures how high land is above sea level. It gets colder as you go higher above sea level, which is why you see snow-capped mountains. | A: elevation. |
A pulley is a simple machine that consists of a grooved wheel and?
Here are the choices:
A. a lever
B. a wedge
C. a battery
D. a rope | Another simple machine that uses a wheel is the pulley. A pulley is a simple machine that consists of a rope and grooved wheel. The rope fits into the groove in the wheel, and pulling on the rope turns the wheel. Figure below shows two common uses of pulleys. | D: a rope. |
What is another name for a broad explanation that is supported by a great deal of evidence?
Here are the choices:
A. theory
B. conjecture
C. hypothesis
D. concept | A : A theory is needed to explain gravity. In science, a theory is a broad explanation that is supported by a great deal of evidence. | A: theory. |
Vinegar is a solution of which acid?
Here are the choices:
A. boric
B. acetic
C. magnesium
D. crystalline | Figure 14.11 Vinegar is a solution of acetic acid, a weak acid. (credit: modification of work by “HomeSpot HQ”/Flickr). | B: acetic. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.