Biotechnology and its Applications

1. Bt cotton is not:

a. A GM plant

b. Insect resistant

c. A bacterial gene expressing system

d. Resistant to all pesticides

Key Answer: d. Resistant to all pesticides

Explanation: Bt cotton is resistant mainly to specific insect pests. It does not provide resistance against all pesticides.

2. C-peptide of human insulin is:

a. A part of mature insulin molecule

b. Responsible for formation of disulphide bridges

c. Removed during maturation of pro-insulin to insulin

d. Responsible for its biological activity.

Key Answer: c. Removed during maturation of pro-insulin to insulin

Explanation: C-peptide connects A and B chains in proinsulin. It is removed to form active insulin.

3. GEAC stands for:

a. Genome Engineering Action Committee

b. Ground Environment Action Committee

c. Genetic Engineering Approval Committee

d. Genetic and Environment Approval committee

Key Answer: c. Genetic Engineering Approval Committee

Explanation: GEAC regulates the use and release of genetically modified organisms. It ensures biosafety and environmental protection.

4. α -1 antitrypsin is:

a. An antacid

b. An enzyme

c. Used to treat arthritis

d. Used to treat emphysema

Key Answer: d. Used to treat emphysema

Explanation: α-1 antitrypsin deficiency can lead to emphysema. The protein helps protect lung tissues from damage.

5. A probe which is a molecule used to locate homologous sequences in a mixture of DNA or RNA molecules could be:

a. A ssRNA

b. A ssDNA

c. Either RNA or DNA

d. Can be ssDNA but not ssRNA

Key Answer: c. Either RNA or DNA

Explanation: Both single-stranded DNA and RNA can hybridize with complementary sequences. Hence either can act as a probe.

6. Choose the correct option regarding Retrovirus:

a. An RNA virus that synthesises DNA during infection

b. A DNA virus that synthesises RNA during infection

c. A ssDNA virus

d. A dsRNA virus

Key Answer: a. An RNA virus that synthesises DNA during infection

Explanation: Retroviruses possess reverse transcriptase enzyme. They form DNA from RNA inside the host cell.

7. The site of production of ADA in the body is:

a. Erythrocytes

b. Lymphocytes

c. Blood plasma

d. Osteocytes

Key Answer: b. Lymphocytes

Explanation: ADA enzyme is mainly produced in lymphocytes. Deficiency causes severe immune disorders like SCID.

8. A protoxin is:

a. A primitive toxin

b. A denatured toxin

c. Toxin produced by protozoa

d. Inactive toxin

Key Answer: d. Inactive toxin

Explanation: Protoxins become active only after specific conditions or reactions. Bt toxin activates in the alkaline insect gut.

9. Pathophysiology is the:

a. Study of physiology of pathogen

b. Study of normal physiology of host

c. Study of altered physiology of host

d. None of the above

Key Answer: c. Study of altered physiology of host

Explanation: Pathophysiology examines functional changes caused by disease. It explains abnormal body processes.

10. The trigger for activation of toxin of Bacillus thuringiensis is:

a. Acidic pH of stomach

b. High temperature

c. Alkaline pH of gut

d. Mechanical action in the insect gut

Key Answer: c. Alkaline pH of gut

Explanation: Bt protoxin becomes active in the alkaline gut of insects. The activated toxin kills insect larvae.

11. Golden rice is:

a. A variety of rice grown along the yellow river in China

b. Long stored rice having yellow colour tint

c. A transgenic rice having gene for β - carotene

d. Wild variety of rice with yellow coloured grains

Key Answer: c. A transgenic rice having gene for β - carotene

Explanation: Golden rice is enriched with β-carotene to reduce vitamin A deficiency. It is developed using genetic engineering.

12. In RNAi, genes are silenced using:

a. ss DNA

b. ds DNA

c. ds RNA

d. ss RNA

Key Answer: c. ds RNA

Explanation: Double-stranded RNA triggers degradation of matching mRNA. This prevents gene expression.

13. The first clinical gene therapy was done for the treatment of:

a. AIDS

b. Cancer

c. Cystic fibrosis

d. SCID (Severe Combined Immuno Deficiency resulting form deficiency of ADA)

Key Answer: d. SCID (Severe Combined Immuno Deficiency resulting form deficiency of ADA)

Explanation: The first successful gene therapy treated ADA deficiency. It restored immune function in SCID patients.

14. ADA is an enzyme which is deficient in a genetic disorder SCID. What is the full form of ADA?

a. Adenosine deoxyaminase

b. Adenosine deaminase

c. Aspartate deaminase

d. Arginine deaminase

Key Answer: b. Adenosine deaminase

Explanation: ADA is essential for normal immune system function. Its deficiency leads to SCID disorder.

15. Silencing of a gene could be achieved through the use of:

a. RNAi only

b. antisense RNA only

c. both RNAi and antisense RNA

d. none of the above

Key Answer: c. both RNAi and antisense RNA

Both RNA interference and antisense RNA block gene expression. They prevent translation of target mRNA.