Q394. Birds usually have a single: (a) Kidney (b) Lung (c)Testis (d)Ovary
OptionD) Male birds have two testes that produce sperm, and most female birds usually have only one ovary that produces eggs. A bird’s testes or ovary greatly increase in size during the breeding season. Their small size during the rest of the year lightens the load for flight. The cloaca is the outlet for eggs or sperm.
