21. Evolution

A species of crayfish that lives in caves produces eyestalks like its above-ground relatives, but has no eyes. Eyestalks in cave-dwelling crayfish are thus ________.

a. An evolutionary error

b. A dominant mutation

c. Biogeographical evidence of evolution

d. A vestigial trait

e. Evidence that evolutionary theory may be incorrect

What type of bond is formed between two sugars in a disaccharide?

a. Glycosidic linkage

b. Phosphodiester bond

c. Peptide bond

d. Hydrogen bond

Which of the following observations helped Darwin shape his concept of descent with modification?

a. Species diversity declines farther from the equator.

b. Fewer species live on islands than on the nearest continents.

c. Birds live on islands located farther from the mainland than the birds' maximum nonstop flight distance.

d. South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe.

What observations did Darwin make on the Galápagos Islands that helped convince him that evolution occurs?

a. The existence of animals that did not fit into Linnaeus's classification system

b. The similarities and differences among cacti and tortoises on the different islands

c. The presence of species he had seen on other tropical islands far from the Galápagos

d. The radioactive age of the rocks of the islands

e. Fossils of human ancestors