Abird's wings are homologous to:
a. an alligator's claws.
b. a fish's tail fin.
c. a dog's front legs.
d. a mosquito's wings.

How does the nervous system affect the excretory system?

How do disease caused by bacteria and disease caused by viruses react to antibiotics

Cancer cells spread to other parts of the body by entering the bloodstream. which of the following organs could prevent a cancer cell in the bloodstream from spreading, and why? a. the spleen, because it releases lymphocytes into the blood b. the peyer's patches, because they release lymphocytes into the blood c. the lymph nodes, because they release lymph into the blood d. the thymus, because it releases lymph into the blood