Answer:
Adaptive immune defense system consists of lymphocytes like B-lymphocytes and T- lymphocytes. B-lymphocytes provides humoral immunity while T- lymphocytes provide cell-mediated immunity to the body.
99% of lymphocytes circulate freely in the blood and lymph. B lymphocytes differentiate into plasma B cells and B memory cells when interact with antigen presented by T helper cells.
Then plasma cells secrete antibodies in the circulation which binds to extracellular antigens through antigen-binding site. Then the bounded antigen is recognized by receptors present on phagocytic cells. This receptor binds the Fc region of antigen bounded antibody and destroy the antigen by phagocytosis.
Giraffes probably used to have short necks. Over time, since the branches of trees or plants were out of their reach, they adapted to this by having a longer neck. Those with longer necks are able to reach the food and eat it that those with short necks could not. Obviously, those with longer necks are able to survive and therefore reproduce. Because of reproduction, they are able to pass on this characteristic that allowed them to survive on to their offspring. This leads to offspring doing the same and over time, affecting the entire population of giraffes and soon evolving giraffes. This is natural selection doing its work in the evolution of long necks in giraffes.
The answer is A. think of qualitative as the quality of the data while the other two options were quantitative. this basically means that there are numbers in the data.
A control group is different because it is not what is being tested. for example the control group would use sugar pills while the other group uses the pills being tested
option C is correct........
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