26) White-crowned sparrows can only learn the “crystallized” song for their species by _____.
A) listening to adult sparrow songs during a sensitive period as a fledgling, followed by a
practice period until the juvenile matches its melody to its memorized fledgling song
B) listening to the song of its own species during a critical period so that it will imprint to its own
species song and not the songs of other songbird species
C) performing the crystallized song as adults when they become sexually mature, as the song is
programmed into the innate behavior for the species
D) observing and practicing after receiving social confirmation from other adults at a critical
period during their first episode of courtship behavior
27) One way to understand how early environment influences behaviors in similar species is
through the “cross-fostering” experimental technique. Suppose that the curly-whiskered mud rat
differs from the bald mud rat in several ways, including being much more aggressive. How
would you set up a cross-fostering experiment to determine if environment plays a role in the
curly-whiskered mud rat’s aggression?
A) You would cross curly-whiskered mud rats and bald mud rats and hand-rear the offspring to
see if any grew up to be aggressive.
B) You would place newborn curly-whiskered mud rats with bald mud rat parents and place
newborn bald mud rats with curly-whiskered mud rat parents. Finally, let some mud rats of both
species be raised by their own species. Then you would compare the outcomes.
C) You would remove the offspring of curly-whiskered mud rats and bald mud rats from their
parents, raise them in the same environment but without parents, and then compare the
outcomes.
D) You would replace normal newborn mud rats with deformed newborn mud rats to see if it
triggered an altruistic response.
28) Which of the following is true of innate behaviors? Innate behaviors _____.
A) are only weakly influenced by genes
B) occur in invertebrates and some vertebrates but not mammals
C) are limited to invertebrate animals
D) are expressed in most individuals in a population