Both because their can be pollution and good things
Answer: Option II.
B cells and T cells undergo colonial selection after encountering an antigen.
Explanation:
B cells are a type of lymphocytes or white blood cells that produce hormones so as to activate the immune system in other to provide a defence or fight against pathogens.
T cells are lymphocytes immune cells that fight against pathogens in the body.
Both T cells and B cells undergo colonial selection after encountering an antigen. The major difference between them is that T cells
Social factors affect the overall survival of the bird.The amount of food an offspring get from the bird (in this case the mother), it determines the weight gain of the offspring, as well as the development of different skills and also its survival.
