Immunity
Read the following passage carefully and answer the given questions.
On daily basis, large number of pathogens are entering our body from the air we breathe in or the food we eat but we are not falling ill daily. It is because of the reason that our body can fight with most of these pathogens entering our body and kill them. Immunity is of two types - acquired or innate immunity. Innate immunity is non specific type of defence which is present from the birth. It is provided by four kinds of barriers - physical, physiological, cellular and cytokine barrier. It is a non specific type of defence. Acquired immunity is acquired when pathogen enters the body. It is pathogen specific and is characterised by memory of the immune system. Acquired immunity is carried out by two special type of lymphocytes called as B-cells and T-cells. B-cells produce antibodies and are responsible for humoral response whereas T-cells produce cell-mediated immune response.
Auto-immune diseases are difficult to manage as:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → It cannot distinguish between ‘self’ and ‘nonself’ cells
The immune system normally tells self cells from nonself cells and attacks only the nonself ones. In an auto-immune disease this fails, and the body attacks its own cells. Rheumatoid arthritis is an example.
(1) It is caused due to genetic and other known reasons — Incorrect. The causes are genetic and other unknown reasons, so they are not all known.
(2) It does not involve giving immunosuppressants to the patients — Incorrect. Drugs that suppress the immune system are part of the treatment. So this is not a reason for the difficulty.
(3) It cannot distinguish between ‘self’ and ‘nonself’ cells — Correct. The defence system itself damages the body’s own cells. The harm comes from the body’s own response, and this makes the disease hard to manage.
(4) It does not retain property of memory — Incorrect. Memory is a property of the acquired immune response, which is the response that carries out the attack. A lack of memory is not the cause.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.
NCERT Extract:
Auto Immunity – …
