Remember that a biotic factor is a living component in an ecosystem that affects the population of another organism. So that means that the answer is B.
Answer: Temperature control
Explanation:
Arterio-venous anastomoses (AVAs) are direct connections between small arteries and small veins. In humans they are numerous in the glabrous skin of the hands and feet.
They are very significant in body temperature control. These temperature control are under the dual control of the central nervous system and the local thermal influence. While the arteriovenous anastomoses control the skin temperature through volume changes in the superficial venous bed, the arterioles and capillaries operate by generalized dilatation which results both in increased temperature and in redness of the skin.
The answer to this question would be: antibody
There are 4 types of hypersensitivity. In type II hypersensitivity, the reaction depends on the antibody. Some of the body cells surfaces were similar to the pathogens that the white blood cells trying to fight. This causing the body also attack the body cells too. It is also called cytotoxic hypersensitivity.
In mismatch transfusion, the receiver recognizes transfused blood cell as foreign material so it was making antibody to fight it.
The outer covering of a reptile egg, may be flexible, calcified eggshells, while there are some reptiles that has hard eggs. A snake lays a kind of reptile egg that is leathery. A reptile egg may differ from one another, depending on the species.