Actual gas exchange occurs through the walls of the ____.​

Which of the following CORRECTLY lists the three forms of nitrogenous waste in order from least to most toxic?

The blood pressure in the aorta is highest during systole.​

Freshwater fish are in a hypotonic environment. How do their gill chloride cells function in this environment?

A biologist discovers a new species of organism adapted to living in a deep underground cavern that provides no source of free water. The organism is eyeless and covered by fur, and it has a four chambered heart with a closed circulatory system. What excretory system adaptations to this extreme environment might the biologist expect to find?

Which of the following statements about freshwater fish is NOT true?

Atherosclerosis is ____.​

When animals excrete nitrogenous waste, what form does it take?

O2 is transported from air in the lungs into the blood through the process of ____.​

Which of the following statements about the control of blood volume and blood pressure is NOT true?