One adaptation to flight in birds is lighter bones, which lack
A. medullary cavities.
B. collagen.
C. the periosteum.
D. bone marrow.
E. calcium.
Answer: D
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The brain perceives the pitch of a sound based on the
a. region of the cochlea sending the signal. b. number of action potentials sent by the neurons. c. speed of the action potentials sent by the neurons. d. size of the action potentials sent by the neurons. e. tension produced along the cochlear membrane.
Which of the following organisms would be considered heterotrophs?
a. most bacteria b. plants c. hydrogen bacteria d. dogs e. most bacteria and dogs
Which of the following is not a lobe of the cerebral hemisphere?
A. reticular B. occipital C. temporal D. frontal E. parietal
Which of the following must occur before cell division begins?
a. duplication of the nucleus b. DNA replication c. cytokinesis d. DNA segregation