Bihar Board - Class 12 Biology - Chapter 12: Biotechnology and Its Applications Long Answer Question

Q.1. What are the disadvantages of GMOs?

A.1. The disadvantages of GMOs are:

• These can harm the insects that are beneficial to our ecosystem.

• It is not a natural way to cultivate plants and hence can damage the environment.

• It causes unwanted residual effects.

• These create more weeds.

• It threatens crop diversity.

• It increases the cost of cultivation.

• It imposes a risk to human health.

Q.2. How can gene expression be controlled with the help of RNA?

A.2. The gene expression can be controlled by RNA interference. It is the process in which the activity of the gene is inhibited by the production of sense and antisense strands.

• Double-stranded RNA would be produced.

• It is cut into short fragments called short interference RNA.

• A silencing complex called RISC incorporates the siRNA.

• RISC cleaves mRNA with a complementary base sequence and makes it silent.

• This is known as mRNA silencing.

Q.3. What are the drawbacks of the insulin obtained from slaughtered cows and pigs?

A.3. The drawbacks of insulin obtained from slaughtered animals are as follows:

• Since insulin is produced in very small amounts in the body, therefore, a large number of animals are slaughtered which is unethical.

• If the slaughtered animals are infected, the insulin will also be contaminated which in turn will infect the acceptor.

• Patients might have a potential immune response against the administered insulin derived from animals.

Q.4. Explain five areas where biotechnology has influenced human lives.

A.4. Biotechnology has influenced human lives as follows:

• Genetically modified crops with high nutritive value are provided by biotechnology.

• It has helped in the production of recombinant vaccines.

• It has devised techniques such as gene therapy for the treatment of genetic diseases.

• Genetically engineered microbes are produced to control environmental pollution.

• Transgenic animals are developed that can produce human proteins.

Q.5. What are transgenic animals? Enlist any four areas where they can be used.

A.5. TRANSGENIC ANIMALS are those whose genetic material has been altered by a gene of interest using genetic engineering techniques. Four areas where they can be used are:

• Transgenic animals serve as experimental models for the study of various human diseases.

• They are used to test vaccines such as polio vaccines.

• Gene expressions help scientists to understand the normal expression of genes at various stages of growth and development.

• They are used to study the side effects of a particular chemical or drug.

Q.6. Explain with an example why are transgenic or genetically modified animals created? 

Ans. Genetically modified or transgenic animals are produced for the given purposes: 

1. To be able to study how genes are regulated and how they affect the normal functioning and development of the body. For example, information gained about the biological role of growth factors like Insulin.

2. Understand how genes contribute to the pathogenesis of the disease. 

3. A useful biological compound is produced by introducing a portion of the DNA encoding for that product in another organism. For example, Antitrypsin can be produced using transgenic organisms. This protein is used in the treatment of emphysema. 

4. To test the vaccine safety. For example, the Polio vaccine was tested in the Genetically Modified mouse. 

5. Toxicity level of the drug can also be tested using transgenic animals.

Q.7. What is Cry Protein? Mention the name of the organism that produces the protein. How did the human use this protein for his benefit? 

Ans. A crystalline protein is produced by the soil bacterium named Bacillus thuringiensis which is known as the 'Cry protein'. This protein is toxic to the larvae of insects such as tobacco buds, beetles, and mosquitoes. The cry protein is produced as an inactive protoxin and is converted to an active toxin when ingested by the insect. The intestinal alkaline pH of insects is capable of solubilizing the crystals of cry protein. The binding of the activated form of cry protein to the midgut of insects creates pores in the intestinal epithelial cells, causing cell lysis and then the death of the insect. The gene encoding this protein contains bacteria and is incorporated in the crops to make them insect-resistant.