NIOS Biology Intext Solutions Chapter 31
INTEXT QUESTIONS 31.1
1. Who is considered as the father of immunobiology?
Ans: Edward Jenner
2. What are the three main functions of immunological defense?
Ans: Broadly, immunological defence serves three functions :
- (i) Defence against microorganisms.
- (ii) Homeostasis, i.e., removal of damaged (non-functional) cells to maintain a normal state.
- (iii) Surveillance, i.e,. recognition and destruction of mutant cells.
3. Define immunology.
Ans: Study of the organisation and function of the immune system.
INTEXT QUESTIONS 31.2
1. Name the two categories of immune cells.
Ans:
(i) Central or primary lymphoid organs.
(ii) Peripheral or secondary lymphoid organs.
2. Name the organ found in birds where B cells are produced.
Ans: Bursa of Fabricius.
3. Write the two main functions of B cells.
Ans: Main functions of B cells:
- (i) Initiate antibody-mediated immune response.
- (ii) Transform into plasma cells that secrete antibodies.
4. Name the cells responsible for synthesis of antibodies.
Ans: Plasma cells/B-cells
5. What is the function of T-helper cells?
Ans: Promote response by B-cells resulting in antibody production, and also activate other T-cells.
INTEXT QUESTIONS 31.3
1. Name the part of antigen which makes contact with antibody.
Ans: Epitope
2. How many types of immunoglobulins are known? (Give only the number).
Ans: Five
3. Name the immunoglobulin found in the highest concentration.
Ans: Immunoglobulin G
4. Which type of immune response is responsible for the killing of cancer cells?
Ans: Cell-mediated immune response
INTEXT QUESTIONS 31.4
1. Mention two physical barriers of the body.
Ans:
- (i) Skin
- (ii) Epithelial cell layer of the respiratory system.
2. Macrophages are found in large numbers in the following organs :
Ans:
- (i) Lung
- (ii) Liver
- (iii) Spleen
3. Give two examples of each of the following:
(i) Killed organism vaccine.
(ii) Live attenuated organism vaccine
(iii) Toxoid vaccine
Ans:
- (i) Typhoid vaccine, Pertussis vaccine.
- (ii) BCG, Rubella vaccine.
- (iii) Diphtheria vaccine, Tetanus vaccine.
