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.
Answer:
The correct answer will be option A.
Explanation:
The bacteria organize its genetic material in the single circular chromosome suspended in the cytosol along with additional circular double-stranded DNA molecule called plasmid.
The plasmid is present as a separate structure in the cytoplasm which performs important functions during stressful conditions in the bacteria like providing antibiotic resistance to the bacteria, formation of filial factors during conjugation and many others.
The plasmid which confers resistant to the bacteria is known as the R-plasmid. The R-plasmid consists of r-determinants which confers antibiotic resistance to the bacteria and resistance transfer factor (RTF) which helps in plasmid transfer.
Thus, option A is the correct answer.
Explanation:
It is true that the wings of the bee move very fast. The wings are smaller than their body and it is believed to be difficult for the wings to lift the whole body of the bee.
Sometimes, bees carry nectar and pollen with itself which again increases their weight. It has been found that the wings do not move up and down rather moves to and from. Since air is denser, it tries to push the air downwards and lift itself upwards.
First answer is , as the work of ventricle is to push blood to he whole body , so it has to be strong or it can not pump blood to head to the toe !
as in frog (an amphibian ) it has only three chambers as two artia and one ventricle, so the oxygenated blood from left artia and deoxygenated blood from right , combines and thus partial oxygenated blood is circulated !
