Which of the following animals has a single-loop closed circulatory system:

a. fish
b. frog
c. human
d. crocodile

In the ocean why are the greatest amount of primary producers found in the epipelagic zone and how does that affect biodiversity

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?

Jason puts an apple on top of an ice pack in his lunch bag lunch time the temperature of the apple has decreased what happens to the molecules in the apple when the temperature of the apple decreases