QUESTIONS AND A+ GRADED
SOLUTIONS
\Q\.Darwin and Wallace were the first to propose ________.
A. that evolution occurs.
B. a mechanism for how evolution occurs.
C. that Earth is older than a few thousand years.
D. natural selection as the mechanism of evolution. - ANSWERS✔-D. natural selection as the
mechanism of evolution.
\Q\.During a study session about evolution, one of your fellow students remarks, "The giraffe
stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a
result." Which statement is most likely to be helpful in correcting this student's misconception?
A. Characteristics acquired during an organism's life are generally not passed through genes.
B. Spontaneous mutations can result in the appearance of new traits.
C. Only favorable adaptations have survival value.
D. Disuse of an organ may lead to its eventual disappearance. - ANSWERS✔-A. Characteristics
acquired during an organism's life are generally not passed through genes.
\Q\.The cow Bos primigenius (which is bred for meat and milk) has a smaller brain and larger
eyes than closely related wild species of ungulates. These traits most likely arose by _____.
,A. natural selection, because these traits evolved in the population over time.
B. natural selection, because these traits were not consciously selected by humans.
C. artificial selection, because changes in these traits co-occurred with human selection for high
milk output and high muscle content.
D. artificial selection, because these animals differ from their close relatives and common
ancestor. - ANSWERS✔-C. artificial selection, because changes in these traits co-occurred with
human selection for high milk output and high muscle content.
\Q\.Parasitic species tend to have simple morphologies. Which of the following statements best
explains this observation?
A. Parasites are lower organisms, and this is why they have simple morphologies.
B. Parasites do not live long enough to inherit acquired characteristics.
C. Simple morphologies convey some advantage in most parasites.
D. Parasites have not yet had time to progress, because they are young evolutionarily. -
ANSWERS✔-C. Simple morphologies convey some advantage in most parasites.
\Q\.Starting from the wild mustard Brassica oleracea, breeders have created the strains known
as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is
correct?
A. In this wild mustard, there is enough heritable variation to permit these different varieties.
B. Heritable variation is low in wild mustard—otherwise this wild strain would have different
characteristics.
C. Natural selection is rare in wild populations of wild mustard.
D. In wild mustard, most of the variation is due to differences in soil or other aspects of the
environment. - ANSWERS✔-A. In this wild mustard, there is enough heritable variation to permit
these different varieties.
, \Q\.A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the
triazine works well and almost all the pigweed dies; but after several years, the farmer sees
more and more pigweed. Which of these explanations best explains what happened?
A. The herbicide company lost its triazine formula and started selling poor-quality triazine.
B. Natural selection caused the pigweed to mutate, creating a new triazine-resistant species.
C. Triazine-resistant pigweed has less-efficient photosynthesis metabolism.
D. Triazine-resistant weeds were more likely to survive and reproduce. - ANSWERS✔-D. Triazine-
resistant weeds were more likely to survive and reproduce.
\Q\.A population of organisms will not evolve if _____.
A. all individual variation is due only to environmental factors.
B. the environment is changing at a relatively slow rate.
C. the population size is large.
D. the population lives in a habitat without competing species present. - ANSWERS✔-A. all
individual variation is due only to environmental factors.
\Q\.If x indicates the location of fossils of two closely related species, then fossils of their most-
recent common ancestor are most likely to occur in which stratum?
A. A
B. B
C. C
D. D - ANSWERS✔-C. C
\Q\.If x indicates the fossils of two closely related species, neither of which is extinct, then their
remains may be found in how many of these strata?