Evolution

Topics in this chapter

• Population Genetics and Allele Change
• Natural Selection and Adaptation
• Speciation and Reproductive Isolation
• Evolutionary Evidence and Common Ancestry
• Origin and Evolutionary History

Cheat sheet

Practice questions

1. Question 1Q-AFD22D

   In a large, randomly mating population at Hardy–Weinberg equilibrium, 9% of individuals show a recessive phenotype. What percentage of the population is expected to be heterozygous?

   1. A.21%
   2. B.42%
   3. C.49%
   4. D.70%
   See the answer and solution
2. Question 2Q-B7260B

   A bacterial population contains a few antibiotic-resistant individuals before exposure to an antibiotic. After exposure, most susceptible bacteria die and resistant bacteria reproduce. Which statement best explains this event?

   1. A.The antibiotic directly creates the required resistance in every surviving bacterium.
   2. B.The antibiotic selects pre-existing resistant variants, increasing their frequency in the population.
   3. C.Individual bacteria develop resistance because they intentionally adapt to the antibiotic.
   4. D.The antibiotic changes the bacteria into a completely different species in one generation.
   See the answer and solution
3. Question 3Q-D10899

   Which of the following is an example of analogous structures?

   1. A.Wings of a butterfly and wings of a bird
   2. B.Forelimbs of a whale and flippers of a seal
   3. C.Thorn of Bougainvillea and tendril of Cucurbita
   4. D.Forelimb of a bat and forelimb of a horse
   See the answer and solution
4. Question 4Q-1DECFF

   Which sequence represents the broad chronological order of appearance of major human evolutionary forms described in evolutionary history?

   1. A.Australopithecines → Homo habilis → Homo erectus → Neanderthals → Homo sapiens
   2. B.Homo erectus → Australopithecines → Homo habilis → Homo sapiens → Neanderthals
   3. C.Homo habilis → Australopithecines → Neanderthals → Homo erectus → Homo sapiens
   4. D.Australopithecines → Homo erectus → Homo habilis → Homo sapiens → Neanderthals
   See the answer and solution
5. Question 5Q-9EA2A6

   The forelimbs of humans, whales and bats have the same basic skeletal arrangement but perform different functions. These structures are best described as:

   1. A.Analogous structures showing convergent evolution
   2. B.Vestigial structures with no evolutionary significance
   3. C.Homologous structures showing divergent evolution
   4. D.Atavistic structures produced by recent mutations
   See the answer and solution