Question 1

Currently,two extant elephant species (X and Y)are placed in the genus Loxodonta,and a third species (Z)is placed in the genus Elephas.Thus,which of the following statements is true?

Accepted Answer

A) Species X and Y are not related to species Z. 
B) Species X and Y share a greater number of homologies than with species Z. 
C) Species X and Y share a common ancestor that is still extant (in other words,not yet extinct). 
D) Species X and Y are the result of artificial selection from an ancestral species Z.

Question 2

Darwin viewed the history of life as a tree,as depicted in the figure,with multiple branchings from a common trunk to the tips of the twigs.  Which part of that tree represents extant organisms?

Accepted Answer

A) tips of the twigs 
B) unlabeled branches 
C) common trunk 
D) forks of the tree

Question 3

According to a 1999 study,the vegetarian finch is genetically no more similar to the tree finch than it is to the ground finch,despite the fact that it is placed in the same genus as the tree finch.Based on this finding,it is reasonable to conclude that the vegetarian finch

Accepted Answer

A) is no more closely related to the tree finch than it is to the ground finch,despite its classification. 
B) should be reclassified as a warbler finch. 
C) is not truly a descendent of the original ancestral finch. 
D) is a hybrid species,resulting from a cross between a ground finch and a tree finch.

Question 4

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes,then what should happen in environments from which antibiotics are missing?

Accepted Answer

A) These genes should continue to be maintained in case the antibiotics ever appear. 
B) These bacteria should be outcompeted and replaced by bacteria that have lost these genes. 
C) The bacteria should try to make the cost worthwhile by locating,and migrating to,microenvironments where traces of antibiotics are present. 
D) The bacteria should start making and secreting their own antibiotics.

Question 5

If two modern organisms are distantly related in an evolutionary sense,then one should expect that

Accepted Answer

A) they live in very different habitats. 
B) they should share fewer homologous structures than two more closely related organisms. 
C) their chromosomes should be very similar. 
D) they shared a common ancestor relatively recently.

Question 6

What was the prevailing belief prior to the time of Lyell and Darwin?

Accepted Answer

A) Earth is a few thousand years old,and populations are unchanging. 
B) Earth is a few thousand years old,and populations gradually change. 
C) Earth is millions of years old,and populations rapidly change. 
D) Earth is millions of years old,and populations are unchanging.

Question 7

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?

Accepted Answer

A) Characteristics acquired during an organism's life are not passed on 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.

Question 8

Two plant species live in the same biome but on different continents.Although the two species are not at all closely related,they may appear quite similar as a result of

Accepted Answer

A) parallel evolution. 
B) convergent evolution. 
C) allopatric speciation. 
D) gene flow.

Question 9

Of the following anatomical structures,which is homologous to the bones in the wing of a bird?

Accepted Answer

A) bones in the hind limb of a kangaroo 
B) chitinous struts in the wing of a butterfly 
C) bony rays in the tail fin of a flying fish 
D) bones in the flipper of a whale

Question 10

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?

Accepted Answer

A) A patient must have become infected with MRSA from another community. 
B) In response to the drug,S.aureus began making drug-resistant versions of the protein targeted by the drug. 
C) Some drug-resistant bacteria were present at the start of treatment,and natural selection increased their frequency. 
D) S.aureus evolved to resist vaccines.

Question 11

Artificial selection is

Accepted Answer

A) human-directed selective breeding. 
B) past extinction. 
C) patterns of evolution. 
D) slower than natural selection.

Question 12

Which of the following best explains the difference between Lamarck's and Darwin's mechanisms for evolution?

Accepted Answer

A) Lamarck believed organisms have an innate drive to become more simple. 
B) Darwin's theory corroborates with current knowledge of inherited traits. 
C) Lamarck had more evidence than Darwin. 
D) Darwin's mechanism of evolution was not based on facts.

Question 13

Within the past century,humans have been eating higher cholesterol and fatty meals and have become less physically active,which makes them more susceptible to heart disease.Which of the following will lead to an adaptation?

Accepted Answer

A) Some people's bodies are able to break down cholesterol and fat more efficiently than others. 
B) Groups of people try going on a daily run. 
C) More people start taking medication for heart disease. 
D) Some people stop eating meals that are high cholesterol and fat.

Question 14

Which of the five common ancestors,labeled V-Z,has given rise to the greatest number of species,both extant and extinct?

Accepted Answer

A) V 
B) W 
C) Both W and Z can be considered to have given rise to the greatest number of extant and extinct species. 
D) Both X and Y can be considered to have given rise to the greatest number of extant and extinct species.

Question 15

What environment stimulates evolution of drug-resistant pathogens?

Accepted Answer

A) presence of an enzyme called penicillinase 
B) colonization of host 
C) pathogens without cell walls 
D) excess antibiotics

Question 16

-According to this tree,what percent of the species seem to be extant (in other words,not extinct)?

Accepted Answer

A) 25% 
B) 33% 
C) 50% 
D) 66%

Question 17

Which of Darwin's ideas had the strongest connection to Darwin having read Malthus's essay on human population growth?

Accepted Answer

A) descent with modification 
B) variation among individuals in a population 
C) the struggle for existence 
D) that the ancestors of the Galápagos finches had come from the South American mainland

Question 18

DDT was once considered a "silver bullet" that would permanently eradicate insect pests.Instead,today DDT is largely useless against many insects.Which of the following should have occurred for this pest eradication effort to be successful in the long run?

Accepted Answer

A) Larger doses of DDT should have been applied. 
B) All habitats should have received applications of DDT at about the same time. 
C) The frequency of DDT application should have been higher. 
D) None of the individual insects should have possessed genomes that made them resistant to DDT.

Question 19

-The diagram shows an outcrop of sedimentary rock whose strata are labeled A-D.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?

Accepted Answer

A) one stratum 
B) two strata 
C) three strata 
D) four strata

Question 20

Logically,which of the following should cast the most doubt on the relationships depicted by an evolutionary tree?

Accepted Answer

A) Some of the organisms depicted by the tree had lived in different habitats. 
B) The skeletal remains of the organisms depicted by the tree were incomplete (in other words,some bones were missing). 
C) Transitional fossils had not been found. 
D) Relationships between DNA sequences among the species did not match relationships between skeletal patterns.

Exam 19: Descent With Modification

Currently,two extant elephant species (X and Y) are placed in the genus Loxodonta,and a third species (Z) is placed in the genus Elephas.Thus,which of the following statements is true?

Darwin viewed the history of life as a tree,as depicted in the figure,with multiple branchings from a common trunk to the tips of the twigs. Which part of that tree represents extant organisms?