NEET Biology Biotechnology and its Applications MCQs Set 08

Answer: (c) Human insulin

Explanation:
1. Human insulin was the first genetically engineered product, made in E. coli.
2. Thyroxin, testosterone and melatonin are not made this way commercially.

Teacher's Note:
1. Humulin was made by Eli Lilly in 1983.
2. The A and B chains were made in separate bacteria and joined by disulphide bonds.

Answer: (d) All of the above

Explanation:
1. To produce an antibiotic by recombinant DNA technology one has to find an antibiotic-producing organism, isolate its gene and join it with a plasmid for expression in E. coli.
2. So all steps are needed.

Teacher's Note:
1. The recombinant plasmid is then cultured in a bioreactor.
2. Product recovery is done by downstream processing.

Answer: (a) Foreign DNA in all its cells

Explanation:
1. A transgenic animal carries an extra, foreign gene as part of its genome, introduced at an early stage.
2. So all its cells carry the foreign DNA.

Teacher's Note:
1. The foreign gene is passed to the next generation.
2. Over 95 percent of transgenic animals are mice.

Answer: (a) Bollworm

Explanation:
1. The genes cryIAc and cryIIAb code for toxins that control the cotton bollworm, while cryIAb controls the corn borer.

Teacher's Note:
1. Bt cotton is resistant to bollworms.
2. The Bt protein forms pores in the midgut of the insect.

Answer: (a) Vitamin A

Explanation:
1. Golden rice is a genetically modified rice enriched with the precursor of vitamin A (beta-carotene).

Teacher's Note:
1. It is meant to tackle vitamin A deficiency.
2. Such rice has a yellow colour.

Answer: (b) C-peptide is removed from proinsulin

Explanation:
1. Proinsulin has chains A and B joined by a connecting C-peptide.
2. During maturation the C-peptide is removed, leaving A and B chains held by disulphide bonds.

Teacher's Note:
1. Mature insulin has only the A and B chains.
2. The C-peptide is absent from mature insulin.

Answer: (c) Tobacco

Explanation:
1. The first transgenic plant was a tobacco plant, produced in the early 1980s.

Teacher's Note:
1. Flavr Savr was the first transgenic crop sold commercially.
2. Tobacco is easy to transform with Agrobacterium.

Answer: (d) Carrying an endotoxin gene from Bacillus thuringiensis

Explanation:
1. Bt stands for Bacillus thuringiensis.
2. Bt cotton carries a gene from this bacterium that codes for an insecticidal crystal (Cry) protein.

Teacher's Note:
1. The toxin is a protoxin that is activated in the alkaline gut of the insect.
2. The active toxin makes pores in midgut cells.

Answer: (a) Bacillus thuringiensis

Explanation:
1. Cry genes code for the crystal proteins of Bacillus thuringiensis.

Teacher's Note:
1. Rhizobium fixes nitrogen.
2. Cry stands for crystal protein.

Answer: (a) Bioinsecticidal plants

Explanation:
1. Bt toxin genes introduced into crop plants make the plants resistant to insect pests, giving bioinsecticidal plants.

Teacher's Note:
1. This reduces use of chemical pesticides.
2. Bt cotton and Bt corn are examples.

Answer: (c) Bollworm

Explanation:
1. Bt cotton makes the Bt toxin that kills the cotton bollworm.
2. It is not meant for roundworms, flukes or pinworms.

Teacher's Note:
1. Bollworms are lepidopteran pests.
2. Nematodes are controlled by the RNA interference approach instead.

Answer: (c) Removed during maturation of insulin

Explanation:
1. The C-peptide connects chains A and B in proinsulin and is removed during maturation.
2. So it is absent from mature insulin, including the insulin made by rDNA technology.

Teacher's Note:
1. Humulin was made by joining separately made A and B chains.
2. This avoided the need for the C-peptide.

Answer: (d) Both 1 and 2

Explanation:
1. The Genetic Engineering Approval Committee (GEAC) decides on the validity of GM research and on the safety of introducing GM organisms for public services.
2. So both 1 and 2 are correct.

Teacher's Note:
1. GEAC was set up by the Government of India.
2. It deals with ethics and safety of GM organisms.

Answer: (b) Biopiracy

Explanation:
1. Biopiracy is the use of bio-resources without proper authorisation and without compensatory payment to the countries and people concerned.

Teacher's Note:
1. Basmati rice and turmeric are well-known cases.
2. A patent on a biological resource is a biopatent.