13.Hematopoiesis is the formation of and takes place in the
a. Bone: red bone marrow
b. Blood cells; red bone marrow
Blood cells; yellow bone marrow
d. Bone; yellow bone marrow

In a certain ecosystem owls are predators for mice. the owl population increases and they eat more mice this causes the mouse population to decrease what happens next? a.the birth of mice increases. b. the birth rate of owls increases c. the population of owls decreases d. the population of mice increases

Common commercial benefits of microorganisms include synthesis ofa. insulin.b. antibiotics.c. aspirin.d. antibiotics and aspirin.e. antibiotics and insulin.

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.