High concentration and passive transport
Atria is a large part of the heart so too big for cells; arteries & veins lead away or to the heart.
Capillaries are the smallest vascular structures that allow materials to be exchanged easily between cells.
The trees dont take in co2 cause there are none cutting off the oxygen cycle
The answer is B.) animals at the end of the food chain would not get enough food to stay alive.
Answer:
its the brain of the cell
Explanation:
