Chapter 15 – Evolution
26. Which of the following is NOT involved in Darwin’s theory of evolution through natural
selection?
27. Permanent change in a given plant population does not occur unless
Chapter 15 – Evolution
28. Approximately half of present-day plant species are believed to have originated in the past
by which of the following events?
29. The development from a single gene pool of two gene pools that are different enough to
prevent interbreeding usually comes about as a result of
Chapter 15 – Evolution
30. Which of the following can play a role in the development of new species from
populations with a common ancestry?
31. Isolating mechanisms, besides that of geography, include which of the following?
Chapter 15 – Evolution
32. The current distribution of eastern: and western: species of redbud (Cercis sp.) is an
example of ________.
33. Analogous features such as spines and fleshy stems of American cacti and African
euphorbias are examples of _______________, adaptation to similar environmental
conditions.
Chapter 15 – Evolution
34. The type of reproductive isolation that occurs when two species mate, but only produce
sterile offspring is referred to as _____________.
35. Hybridization between two closely related species followed by doubling of all sets of
chromosomes results in a/an __________________ that is ___________. [first word fills in
the first blank; second word, the second blank.]
Chapter 15 – Evolution
True / False Questions
36. Modern theories of evolution recognize that mutation, recombination of genes through
hybridization, and polyploidy (at least in plants) are essential to allowing the development of
a new species.
37. The least complex fossils generally are found in the oldest geological strata.
38. When a piece of one chromosome becomes attached to another, it is called translocation.
Chapter 15 – Evolution
39. Most mutations are harmful to the cell in which they occur.
40. Genetic drift can bring about evolutionary changes but only in populations of very large
size.
41. Apomixis requires a special form of meiosis.
42. New species cannot develop without geographical isolation.
Chapter 15 – Evolution
43. The majority of mutations are favorable to the adaptation of organisms to their
environment.
44. Sterile hybrids may reproduce by asexual means.
45. Gene flow occurs when a strong wind blows significant number of seeds from one
population into a second population.
Chapter 15 – Evolution
46. One aspect of Darwin’s theory was that living organisms are unchanging, appearing today
exactly as their ancestors have always appeared.
47. A triploid individual that has three sets of identical chromosomes is called a autoploid.
48. Individuals producing the greatest number of viable offspring are said to be the most fit.
Chapter 15 – Evolution
49. Lamarck is best known for his theory of inheritance of acquired characteristics.
50. Survival of the fittest meant to Darwin that those individuals best able to survive a cold
winter, for example, would leave less offspring than those organisms that entered a dormant
condition in winter.
51. One key to the origin of new species is geographic isolation.
Chapter 15 – Evolution
52. Darwin spent his time aboard the sailing vessel H. M. S. Beagle as the ship’s medical
doctor.
53. Deletions, translocations, and inversions are chromosomal changes that lead to mutations.
54. In addition to his work on natural selection, Charles Darwin is recognized as the pioneer
of scientific naming.