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Choose the answer that best describes the scientific method:
A) guess, hypothesis, experiment, conclusion
B) observation, hypothesis, experiment, conclusion
C) hypothesis, experiment, observation, conclusion
D) experiment, observation, hypothesis, conclusion
Which of the following solutions has the greater concentration of hydrogen ions (H+) and therefore is more acidic?
A) seawater at pH 8
B) gastric juice at pH 2
C) black coffee at pH 5
D) tomatoes at pH 4
E) vinegar at pH 3
What is the primary reason for including a control within the design of an experiment?
A) To insure that the results obtained are due to a difference in only one variable.
B) To test the effect of more than one variable.
C) To demonstrate in what way the experiment was performed incorrectly.
D) To accumulate more facts that can be reported to other scientists.
Hydrogen bonds occur between:
A) the oxygen atom of one water molecule and a hydrogen atom of an adjacent molecule
B) hydrogen atoms of adjacent water molecules
C) the oxygen atom of one water molecule and the two hydrogen atoms of the same water molecule
D) hydrogen atoms of the same water molecules
The atomic mass (sometimes also called the atomic weight) of an atom:
A) is dependent on its physical state
B) equals the number of protons and neutrons
C) is equal to its atomic number
D) equals the number of protons and electrons
E) equals the number of protons
Which of the following statements about water is correct?
A) Compared to most other substances, the temperature of water rises sharply when it absorbs heat.
B) Water is less dense as a solid than it is as a liquid.
C) Water is a good solvent for lipids.
D) Water is not necessary for life on Earth.
Which of the following are properties of ALL life forms? 1. heritable programs in the form of DNA 2. photosynthesis 3. growth and development
A) Only 1 and 3 are correct.
B) 3
C) 1
D) 1, 2, and 3 are correct.
E) 2
A covalent bond is:
A) an example of a hydrogen bond
B) a sharing of electrons between two atoms
C) an attraction of charged ions
D) the transfer of one electron from one atom to another
The atomic number of an element equals the number of:
A) protons and electrons
B) electrons
C) protons
D) neutrons
E) protons and neutrons
If neutral atoms become negative ions, they:
A) do not change
B) gain protons
C) lose electrons
D) lose protons
E) gain electrons
Which of the following are properties of ALL life forms? 1. heritable programs in the form of DNA 2. photosynthesis 3. growth and development
A) 1, 2, and 3 are correct.
B) 1
C) Only 1 and 3 are correct.
D) 2
E) 3
Crossing-over allows for an exchange of genetic material between sister chromatids.
A) False
B) True
Drug companies claim that it costs them between $500 million and $1 billion to bring a single new medicine to market. Who should bear the cost of expensive drug therapy?
A) The insurance companies should pick up the cost.
B) Patients should be willing to pay for their own drug therapy.
C) The government should pay for the drugs through increased taxes.
D) The drug companies should bear the costs through their private research.
E) This is a complex issue that cannot be answered by any one entity.
If a crayfish has 200 total chromosomes in its body cells (not ovaries or testes)
A) 50 pairs or 100 total would come from the father and 50 pairs from the mother.
B) they would consist of 100 pairs with one of each pair from the father, one of each pair from the mother.
C) all 200 come from the mother in a female crayfish, all 200 from the father in a male crayfish.
D) as many as none-to-200 came from the father and conversely, from 200-to-none would have come from the mother.
E) any 100 could have been from its father and any 100 from its mother.
During crossing-over,
A) mitosis becomes meiosis.
B) chromosomes become chromatin.
C) chromatids exchange segments of genetic material.
D) chromatin becomes chromosomes.
E) chromosomes switch poles.
Meiosis results in a change in chromosome number indicated by
A) 2n to 2n in diploid organisms, n to n in haploid.
B) n to n.
C) n to 2n.
D) 2n to n.
E) 2n to 2n.
Which stage is most associated with a cell unable to divide again, such as a muscle or nerve cell?
A) M phase
B) All of choices are involved in controlling cell division.
C) S phase
D) G phase
If the total number of chromosomes in a cell is six, then after mitosis there will be
A) two chromosomes in each daughter cell, one from each parent.
B) six chromosomes in each daughter cell.
C) three chromosomes in each daughter cell.
D) three chromosomes in one daughter cell and six chromosomes in the other cell.
E) 12 chromosomes in each daughter cell.
During ____, the sister chromatids will move away from each other.
A) prophase
B) anaphase I
C) metaphase II
D) metaphase I
E) anaphase II
Mitotic division is the normal process of cell reproduction to build and maintain the body of an organism, while meiosis takes place only in the formation of gametes for reproduction.
A) True
B) False
In plants, cytokinesis occurs with the formation of
A) a cleavage furrow of the nuclear membrane.
B) a cleavage furrow of the cell wall.
C) a cell plate.
D) a cleavage furrow of the cytoplasm.
E) asters and centrioles.
Which is NOT a correct association?
A) G1 stage-cell grows in size and cell organelles increase in number
B) G2 stage-metabolic preparation for mitosis
C) G0 stage-most active stage of repeated duplication and division
D) S stage-DNA synthesis
E) M stage-mitosis and cytokinesis
In mitosis, the chromosomes line up on the equatorial plane of the cell during
A) interphase.
B) metaphase.
C) telophase.
D) prophase.
E) anaphase.
How does cell division differ between animal and plant cells?
A) Plant cells resort to binary fission.
B) Animal cells lack centrioles and no asters form during cell division.
C) All of the choices are incorrect.
D) Plant cells form a cleavage furrow or indentation of membrane between new daughter cells.
E) The cell plate is the final partitioning of plant cells.
During mitosis, separation of the sister chromatids ensures that each daughter cell will receive two copies of each type of chromosome.
A) True
B) False
Centrioles are absolutely necessary to the process of mitosis in all organisms.
A) True
B) False
Which is NOT a correct association?
A) somatic-cells of the body not involved in gamete production and which undergo mitosis
B) centromere-point where sister chromatids remain attached
C) cytokinesis-division of the cytoplasm
D) sister chromatids-two identical chromosome strands still attached at the centromere
E) mitosis-when a cell duplicates and then divides twice to reduce chromosome number by half
The difference(s) between spermatogenesis and oogenesis is(are)
A) spermatogenesis results in four times more cells.
B) oogenesis produces polar bodies in an effort to keep nutrients for the one egg cell.
C) oogenesis stops at the second meiotic division and awaits fertilization by a sperm before finishing meiosis.
D) All of the choices are correct.
Where would we expect the most active cell cycling?
A) nerve cells
B) All cells cycle at the same general rate.
C) stem cells producing epidermis and blood cells
D) skeletal muscle cells
The overall cell cycle is dramatically different for animals than for plant cells.
A) False
B) True
Cancer is more likely to develop in tissues whose
A) cells go through mitosis frequently, e. g., blood-forming cells in the bone marrow.
B) cells are lacking mitochondria.
C) It does not matter if cells go through mitosis frequently or infrequently.
D) cells do not go through mitosis frequently, e. g., nerve cells.
Most of Darwin's observations about changes in species over time and in different environments took place in and near
A) North America.
B) South America.
C) Asia.
D) Europe.
E) Australia.
Lamarck's ideas on evolution were adopted by some Russian scientists, including Michurin and Lysenko in Stalinist Russia. Their textbooks printed Lysenko's assertions that a wheat plant could be made cold-hardy by conditioning in cold storage, or that workmen who develop strong muscles would produce children who would be born stronger. Which of the major premises of evolution by natural selection was violated?
A) The organisms vary in traits.
B) The variation is inherited.
C) More young are born than can survive.
D) Some individuals are better adapted to the environment.
Handedness is considered to be genetically determined, with right-handedness being dominant and left-handedness recessive. A student proposes that handedness could just as easily be passed to children by how the parents carry the child and interact with it, a learning process that may perpetuate the parents' handedness. Assuming all parents and children are expressing their "true handedness," the occurrence of which case below would cast the most serious doubt on a simple genetic basis for handedness, with left handedness recessive?
A) Right-handed parents only have right-handed children.
B) None of the choices are correct.
C) Two left-handed parents have a right-handed child.
D) Left-handed parents only have left-handed children.
E) Two right-handed parents have a left-handed child.
Which statement is NOT true about natural selection?
A) Directional selection leads to improved selection when the environment remains the same.
B) Directional selection occurs when one extreme phenotype is favored over another different extreme phenotype.
C) Disruptive selection leads to polymorphism, favoring different forms of the same species.
D) Stabilizing selection favors an intermediate phenotype over either of the extreme phenotypes.
E) Disruptive selection favors both of the extreme phenotypes over the intermediate phenotype.
If two adjacent populations of the same species show gene flow, then the two populations will
A) develop into different species.
B) become more similar in their gene pools.
C) adapt to different conditions and become separate.
D) become isolated from each other.
Which of the following mechanisms does NOT result in variation in the gene frequencies from the ancestral population?
A) genetic drift
B) natural selection
C) differential reproduction
D) founder effect
E) recombination of alleles
Which statement is NOT true about nonrandom mating?
A) Inbreeding is mating between relatives more often than by chance.
B) Assortative mating tends to cause subdivision into two phenotypic classes with reduced gene flow between them.
C) An example of assortative mating is when a tall man marries a tall woman.
D) Inbreeding is a change in allele frequencies that increases the proportion of heterozygotes in the population.
A wide range of evidence has been brought together to describe what constitutes a species. From all of this you can conclude that
A) a species can be definitively described by DNA hybridization, DNA sequencing, or enzymes.
B) some day we could theoretically finalize a list of all species on earth and, if correct, it could remain unchanged.
C) None of the choices are correct.
D) just as organisms recognize their own species, all levels of taxa [class, order, family, genus] are naturally occurring entities.
E) once mating experiments have been conducted and fertile offspring detected, a species can be defined with absolute certainty.
Genetic drift produces changes in allele frequencies within a gene pool due to chance.
A) True
B) False
The case of peppered moths in England is an example of stabilizing selection.
A) False
B) True
The proliferation of Darwin's finches is an example of adaptive radiation.
A) False
B) True
Transitional forms are seen in the fossil record that link all of these groups EXCEPT
A) mammals and reptiles.
B) birds and reptiles.
C) mammals and birds.
D) reptiles and amphibians.
E) fish and amphibians.
The new model of evolution that proposes that organisms spend most of their time in fairly unchanging form and undergo occasional bursts of speciation is called
A) phyletic gradualism.
B) sympatric speciation.
C) genetic drift.
D) punctuated equilibrium.
E) the biological species concept.
Which of the following is true about genetic drift?
A) It increases the number of heterozygotes in a population.
B) It is more likely to occur in a large population than in a small population.
C) It may lead to an allele becoming fixed in a population when its alternative allele is lost from the population.
D) It increases the level of rare alleles in a population.
Natural selection was independently proposed as a means of evolution by Darwin and
A) Lamarck.
B) Lyell.
C) Wallace.
D) LeClerc.
Which fossil evidence is considered an intermediate between reptiles and birds?
A) synapsids
B) Seymouria
C) Archaeopteryx
D) Eustheopteron
E) therapods
Which of the following is a reason why life does NOT arise today?
A) There is too much pollution.
B) There is no ozone shield.
C) There is an oxidizing atmosphere.
D) There is a reducing atmosphere.
What is the term used to describe the accumulation of small changes in the gene pool of a species over time?
A) genetic drift
B) directional selection
C) founder effect
D) microevolution
A variety of genotypes and phenotypes in a population is useful because it
A) makes genetic drift an unlikely occurrence.
B) makes life more interesting.
C) allows the species to survive if the environment changes.
D) means that the gene pool is constant and unchanging.
The model of speciation that requires some time with geographic barriers between two populations allowing evolution of reproductive isolation is
A) sympatric speciation.
B) phyletic gradualism.
C) punctuated equilibrium.
D) allopatric speciation.
E) the biological species concept.
Which is NOT a parasitic relationship?
A) The Dutch elm disease fungus infects and kills elm trees.
B) The trichina worm burrows into muscle tissue, forms a cyst, and waits to continue its cycle until a predator consumes the host.
C) A female tick fastens to the skin of a human host and draws blood for nutrition to make her eggs.
D) Unsightly dandelions sprout in a yard and compete with the fescue grass for sunlight.
E) The yellow fever virus causes fever and sometimes kills humans.
Which is NOT a density-dependent factor?
A) weather
B) food supply
C) disease
D) predators
E) shelter or nest space
Replacement reproduction cannot bring about zero population growth unless
A) all diseases such as cholera, typhus, and diphtheria are brought under control.
B) there are as many older women leaving the reproductive years as there are younger women entering them.
C) there are many fatalities due to a world war.
D) None of the choices are true.
Which term describes the concept that no two species can have the same "job" in the community at the same time?
A) symbiosis
B) competitive exclusion
C) niche
D) habitat
E) mimicry
Parasites are found
A) only as viruses, bacteria, protists, and animals; no plants are parasites because they cannot move.
B) only on one host where they can complete their life cycle and disperse to others of that same species.
C) only as viruses, bacteria, and protists.
D) in all kingdoms and sometimes one parasite uses more than one host to disperse.
E) only on host animals.
Which of the following statements accurately describes the less developed countries?
A) high birthrate, different age groups of equal size
B) high birthrate, large pre-reproductive portion of the population
C) high growth rate, reproductive portion of the population is the largest
D) low growth rate, different age groups of equal size
In Figure 33.1, where does the effect of environmental resistance first begin to show on the graph?
A) 4
B) 1
C) 2
D) 3
A scientist observes a population of grasshoppers in a farmers field several times over the summer. She notices that after each application of an insecticide the grasshopper population increases to its pre-pesticide levels very rapidly and that the population never goes near zero at any time. The scientists results indicate the grasshopper population is probably
A) in the exponential growth phase.
B) in the lag phase.
C) in the stable equilibrium phase.
D) in the deceleration phase.
Your front yard represents a(n) _______ while the leafhoppers represent a(n) ______.
A) population; ecosystem
B) population; community
C) community; population
D) ecosystem; population
E) ecosystem; community
Consider that a species of salmon lays 20,000 eggs per pair when it spawns and dies. At the end of five years, an average of one pair of mature salmon from this group of hatched eggs returns again to spawn in the parent stream (19,998 have died). What is the rate of natural increase?
A) zero, because there is exact replacement of the previous generation
B) -2,000, because there was this much average die-off per year
C) 10,000, because there were that many eggs produced per parent fish (r)
D) 2,000, because this must be divided by five years
E) -19,998, because there was this much total loss
The human growth curve is best described as being
A) S-shaped.
B) V-shaped.
C) J-shaped.
D) flat.
E) W-shaped.
In a Canadian study, it was shown that the size of a snowshoe hare population was related to the size of the predatory lynx population.
A) True
B) False
Interaction between two species as both attempt to use the same environmental resources is
A) competition.
B) predation.
C) symbiosis.
D) a community.
E) an ecosystem.
A probable example of commensalism is
A) termites with protozoa in their digestive tracts.
B) ants living on the bullhorn acacia tree.
C) the snowshoe hare and the Canadian lynx.
D) flowering plants and their pollinators.
E) remoras riding on the belly of a shark.
If a harmful relationship decreases the survival of the harmed member in the dependent relationship, we can expect that evolution over time would lead in which direction?
A) parasitism to mutualism to altruism to commensalism.
B) commensalism to parasitism to predation
C) mutualism to commensalism to parasitism to mutualism
D) commensalism to parasitism to mutualism
E) parasitism to commensalism to mutualism
Which of the following IS NOT a form of environmental resistance?
A) Accumulation of waste products
B) Number of offspring produced per litter
C) Limited food supply
D) Predation
A population with rapidly expanding exponential growth would be best represented by a graph with a/an ______-shaped curve.
A) bell
B) S
C) urn
D) pyramid
E) J
The yucca moth is the only pollinator of the yucca plant and the plant cannot produce seeds without the moth carrying pollen among flowers. In return, the yucca moth lays eggs in the yucca flower and the moth larvae harvest a small proportion of the resulting seeds. Since the future fate of these two species is tied together in this fashion, the relationship is
A) an ecosystem.
B) benevolent predation.
C) controlled competition
D) competitive symbiosis.
E) coevolution.
Biological growth rate would be negative when
A) better health care reduces the death rate and increases survivorship of newborns.
B) all couples are married but average less than two children apiece.
C) a country becomes poorer, because it is related to economic growth.
D) death rate is greater than birth rate.
E) birth rate is greater than death rate.
The study of the interrelationships of plants and animals with each other and with their environment is known as
A) a biosphere.
B) a food web.
C) a habitat.
D) a trophic level.
E) ecology.
The proposed cause of CJD, mad-cow disease, scrapie in sheep, and kuru in cannibals from the New Guinea highlands is a change in a brain protein. Disease victims appear to have a normal protein that should contain primarily coiled alpha helix changed into a protein mainly made of pleated beta sheets. This would constitute a change in the
A) quaternary structure.
B) secondary structure.
C) linear sequence of the amino acids or its primary structure.
D) protein into a nucleic acid.
E) tertiary structure.
n the search to discover the agents that caused mad cow disease, scrapie in sheep, and CJD and kuru in humans, the diseased brain tissues were filtered and still found to be infective, indicating they are not bacteria but either viruses or chemical molecules. If it was a virus, the infective agent would contain either RNA or DNA. Other possibilities were that the agent was a carbohydrate or a fat or a protein. Infective tissues were treated with agents that destroyed just one of these chemicals and then injected into a healthy animal, with the results as follows. What is the infective agent?

•Amylase digests carbohydrates; tissue still infects healthy test animal.
•Lipase digests fats; tissue still infects healthy test animal.
•Formaldehyde and/or heat denatures DNA and RNA; tissue still infects healthy test animal.
•Trypsin digests protein; tissue does not infect healthy test animal.
A) fat
B) Could be carbohydrate, fat, or DNA or RNA but not protein.
C) carbohydrate
E) protein
Cholesterol is an example of a steroid lipid.
A) False
B) True