Target Exam

CUET

Subject

Biology

Chapter

Biotechnology and its Applications

Question:

Read the following paragraph and answer the given questions.

RNAi takes place in all eukaryotic organisms as a method of cellular defense. The source of this complementary RNA could be from an infection by viruses having RNA genomes or mobile genetic elements (transposons) that replicate via an RNA intermediate. Insulin from an animal source, though caused some patients to develop allergy or other types of reactions to the foreign protein. Insulin consists of two short polypeptide chains: chain A and chain B, that are linked together by disulphide bridges. Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. Transgenic mice are being used to test the safety of the polio vaccine. If successful and found to be reliable, they could replace the use of monkeys to test the safety of batches of the vaccine. Specific Bt toxin genes were isolated from Bacillus thuringiensis and incorporated into the several crop plants such as cotton. The choice of genes depends upon the crop and the targeted pest, as most Bt toxins are insect-group specific. The toxin is coded by a gene cry/Ac named cry. There are a number of them, for example, the proteins encoded by the genes cry/Ac and cryllAb control the cotton bollworms, that of crylAb controls corn borer.

Identify the incorrect fact about the genetic modification?

Options:

It has made crops more tolerant to abiotic stresses (cold, drought, salt, heat).

It has helped to reduce post harvest losses.

It has decreased the nutritional value of food, e.g., golden rice, i.e., Vitamin 'A' enriched rice.

It has reduced reliance on chemical pesticides (pest-resistant crops).

Correct Answer:

It has decreased the nutritional value of food, e.g., golden rice, i.e., Vitamin 'A' enriched rice.

Explanation:

The correct answer is Option (3) - It has decreased the nutritional value of food, e.g., golden rice, i.e., Vitamin 'A' enriched rice.

Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO). GM plants have been useful in many ways. Genetic modification has:

(i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat).

(ii) reduced reliance on chemical pesticides (pest-resistant crops).

(iii) helped to reduce post harvest losses.

(iv) increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil).

(v) enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’ enriched rice