question_answer

(i) Mention the two corollaries that have to be understood about memory based acquired immunity.

(ii) Why is the phenomenon of metastasis considered fatal?

Answer:

(i) Two corollaries that have to be understood about memory based acquired immunity are

(a) Higher vertebrates can distinguish foreign organisms from their self-cells.

(b) Due to genetic or unknown reasons, body attacks self-cells and causes autoimmune diseases.

(ii) Metastasis is the phenomenon where sloughing off of tumour cells occur, which reach other parts of body via blood and start a new tumour. It is a very fatal property of malignant tumours.