For the first one I’d say D
The answer for the 2nd one is C.
Explanation:
The main building material in the body.
They are carriers of vitamins, hormones, fatty acids and other substances.
Provide the normal functioning of the immune system.
Provide the state of the "apparatus of heredity".
They are catalysts of all biochemical metabolic reactions of the body.
Answer:
Negative feedback.
Explanation:
The production of erythropoietin by the liver and kidneys is a negative feedback because with the production of erythropoietin, our body tends to move to become more stable state. The erythropoietin is produced by the liver and kidneys to increase the production of red blood cells if the quantity of red blood cells are lower than the normal range. If the number of red blood cells are decreases the oxygen level in our body is low that leads to unstable condition of the body but when the concentration of red blood cells increases, the body move towards stability.
The primary function of all lymph nodes is the production of lymphocytes, which help defend the body against microorganisms and against harmful foreign particles and debris from lymph before it is returned to the blood stream. The major clusters of lymph nodes are in six areas.
