Biology Ch. 22

Currently, two of the living elephant species (X and Y) are placed in the genus Loxodonta, and a third surviving species (Z) is placed in the genus Elephas. Assuming this classification reflects evolutionary relatedness, which of the following is the most accurate phylogenetic tree?

D

Which of these conditions are always true of populations evolving due to natural selection? A) Conditions 1 and 2 B) Conditions 2 and 3 C) Condition 2 only D) Condition 1 only

A) Conditions 1 and 2

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) In wild mustard, most of the variation is due to differences in soil or other aspects of the environment. C) Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics. D) Natural selection is rare in wild populations of wild mustard.

A) In this wild mustard, there is enough heritable variation to permit these different varieties.

Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of ________. A) natural selection B) a vestigial trait C) convergent evolution D) a homologous structure

B) A vestigial trait

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 statements explains why the pigweed reappeared? A) Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. B) Triazine-resistant weeds were more likely to survive and reproduce. C) Triazine-resistant pigweed has less-efficient photosynthesis metabolism. D) The herbicide company lost its triazine formula and started selling poor-quality triazine.

B) Triazine-resistant weeds were more likely to survive and reproduce.

The questions below refer to the following evolutionary tree, in which the horizontal axis represents time (present time is on the far right) and the vertical axis represents morphological change. Which species is most closely related to species W? A) X is most closely related to species W. B) V is most closely related to species W. C) Y and Z are equally closely related to W. D) It is not possible to say from this tree.

B) V is most closely related to species W.

Given what we know about evolutionary biology, we expect to find the largest number of endemic species in which of the following geological features, which have existed for at least a few million years? A) an extensive mountain range B) an isolated ocean island in the tropics C) a grassland in the center of a large continent, with extreme climatic conditions D) a shallow estuary on a warm-water coast

B) an isolated ocean island in the tropics

Darwin used the phrase "descent with modification" to explain ________. A) that habitat differences stimulate change in organisms B) evolution of the unity and diversity of life C) descent of all organisms from a single, ancient ancestor D) unity of life

B) evolution of the unity and diversity of life

What are adaptations? A) descent with modification from a common ancestor B) inherited characteristics of organisms that enhance their survival C) geologic changes over time D) rocks containing fossils

B) inherited characteristics of organisms that enhance their survival

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of ________. A) the evolution of similar appearance as a result of common function B) the evolution of common structure as a result of common function C) homology D) convergent evolution

C) Homology

Which of the following is not an observation or inference on which natural selection is based? A) There is heritable variation among individuals. B) Species produce more offspring than the environment can support. C) Poorly adapted individuals never produce offspring. D) Only a fraction of an individual's offspring may survive.

C) Poorly adapted individuals never produce offspring.

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S.aureus infections were caused by MRSA. How can this best be explained? A) S. aureus evolved to resist vaccines. B) A patient must have become infected with MRSA from another community. C) In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug. D) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

D) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it: A) was the first time a biologist had proposed that species changed through time B) was the first theory to refute the ideas of special creation C) proved that individuals acclimated to their environment over time. D) dismissed the idea that species are constant and emphasized the importance of variation and change in populations

D) dismissed the idea that species are constant and emphasized the importance of variation and change in populations

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that: A) humans evolved from chimpanzees. B) chimpanzees evolved from humans. C) convergent evolution led to the DNA similarities. D) humans and chimpanzees share a relatively recent common ancestor.

D) humans and chimpanzees share a relatively recent common ancestor.

Which of the following evidence most strongly supports the common origin of all life on Earth? All organisms ________. A)show heritable variation B) require energy C) reproduce D) use essentially the same genetic code

D) use essentially the same genetic code