Primary immune response occurs due to the first exposure of an antigen to the immune system. The primary immune response is generally delayed by many days because it takes time for B and T cells to become cloned and to proliferate and differentiate.

Then after several days of proliferation and differentiation of activated T and B cells, T cells become effector T cells and B cell becomes plasma cells which then eliminates the antigen. Memory B and T cells are also produced during this process which helps in generating a quick immune response during the second and subsequent exposure of that antigen.

So the correct answer is D. proliferation and differentiation.

7 0

2 years ago

The urethra carries urine outside of the body, and the corpus cavernosum carries sperm outside of the body. true false

Elina [12.6K]

Answer: False

Explanation:

The urethra is a tube which runs from the bladder to the end of the penis. It functions by carrying the urine and semen outside the male body.

Urethra is made of two components. Prostatic urethera is the part that runs from the bladder through the prostrate.

The penis is only organ which carries both the fluids out of the body.

4 0

3 years ago