The effectiveness of geographic barriers in promoting speciation is related most to ____
a. the absolute size of the barrier
b. the inability of the organisms to overcome the barrier
c. the speed at which the barrier forms
d. how long the barrier exists
e. the size of the population it separates
ANSWER: b
You might also like to view...
Animals with bilateral symmetry typically undergo an evolutionary process whereby many nerve cells and sensory structures become concentrated at the front of the body. What is this process called?
a. segmentation b. cephalization c. coelom formation d. pupation e. radiation
____ are believed to have once existed as independent prokaryotes
a. Bacteriophages b. Chloroplasts c. Slime molds d. Protists e. Nuclei
Distilled water refers to water that is nearly free of
a. solutes. b. ions. c. gases. d. suspended solids. e. none of these.
Although the genetic contributions of egg and sperm
nuclei are equal, the egg contributes more to cell differentiation because of a. its energy reserves. b. its cytoskeletal elements. c. its specialized proteins. d. its maternal messages. e. all of these.