Choose the incorrect statements from the following:
A. Memory-based acquired immunity evolved in lower vertebrates based on the ability to differentiate foreign organisms from self-cells.
B. Higher vertebrates can distinguish foreign molecules as well as foreign organisms.
C. Sometimes, due to genetic and other unknown reasons, the body attacks self-cells; this results in damage to the body and is called allergy.
D. The body is able to differentiate ‘self’ and ‘non-self’, and the cell-mediated immune response is responsible for graft rejection.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A and C only
Acquired immunity rests on the body’s ability to tell foreign organisms from its own cells. When this ability fails and the body attacks its own cells, the result is an auto-immune disease. Allergy is a different thing: an exaggerated response to antigens in the environment.
A. Memory-based acquired immunity evolved in lower vertebrates based on the ability to differentiate foreign organisms from self-cells. — An incorrect statement. The book says it evolved in higher vertebrates, not lower vertebrates.
B. Higher vertebrates can distinguish foreign molecules as well as foreign organisms. — A correct statement. This is one of the two corollaries of the ability to tell self from non-self.
C. Sometimes, due to genetic and other unknown reasons, the body attacks self-cells; this results in damage to the body and is called allergy. — An incorrect statement. An attack of the body on its own cells is called an auto-immune disease, for example rheumatoid arthritis. Allergy is the exaggerated response to allergens such as pollen and dust mites.
D. The body is able to differentiate ‘self’ and ‘non-self’, and the cell-mediated immune response is responsible for graft rejection. — A correct statement. A graft from an unmatched source is seen as non-self, and the cell-mediated immune response rejects it.
NCERT Extract:
Auto Immunity – “Memory-based acquired immunity evolved in higher vertebrates based on the ability to differentiate foreign organisms (e.g., pathogens) from selfcells. While we still do not understand the basis of this, two corollaries of this ability have to be understood. One, higher vertebrates can distinguish foreign molecules as well as foreign organisms. Most of the experimental immunology deals with this aspect. Two, sometimes, due to genetic and other unknown reasons, the body attacks self-cells. This results in damage to the body and is called auto-immune disease.”
Acquired Immunity – “… The body is able to differentiate ‘self’ and ‘nonself’ and the cell-mediated immune response is responsible for the graft rejection.”