What occurs when blood from the lungs enters the left atrium a. blood is deoxygenated
b. second circulatory loop begins
c. first circulatory loop begins
d. blood flows directly into the veins

Study the picture of the ocean. which is the best example of an organism’s niche shown in the picture? a. the environment contains several of the same species of coral. b. the shallow area of the ocean meets the needs of the coral and the fish. c. the ocean has fish and coral that live in the same area. d. the coral take in food from the water and provide shelter for the fish.

In an hydrogen ion pump the energy is used to join small molecules together to make larger ones which factor most likely has the greatest effect on the number of molecules mitochondria can produce

Atype of organism that no longer exist on earth is said to be