Sunday, January 3, 2021

Biotechnology and its Applications | Class 12 Botany| Previous Years Questions and Answers (2018 to 2020)

5. BIOTECHNOLOGY: APPLICATIONS


2020 SAY


1.   Fill in the blank: (1)

Alpha I-antitrypsin is used to treat the disease ...................

ü Answer:

Emphysema

2.   Expand GEAC and ADA. (2)

ü Answer:

GEAC = Genetic Engineering Approval Committee.

ADA = Adenosine deaminase.

3.   Bt cotton contains cry genes from a bacterium. (2)

(a)    Name that bacterium

(b)   Give two examples for cry genes.

ü Answer:

(a) Bacillus thuringiensis.

(b) cryIAc, cryIAb, cryIIAb

2020 MARCH

1.   How does the inactive protoxin of Bacillus thuringiensis gets converted into active toxin when an insect ingests it? (2)

ü Answer:

When an insect ingests the toxin, it becomes active due to alkaline pH of the gut which solubilise the crystals. Toxin binds to surface of epithelial cells creating pores. It causes death of the insect.

2.   Early diagnosis is essential for the effective treatment of a disease. Write any two molecular diagnostic methods. (2)

ü Answer:

Polymerase Chain Reaction (PCR).

Enzyme Linked Immuno-Sorbent Assay (ELISA).

Autoradiography etc.

2019 SAY June

1.   Alpha-I antitrypsin and alpha-lactalbumin are two biological products produced from transgenic animals. Write the uses of these two products. (2)

ü Answer:

Use of Alpha-I antitrypsin: To treat emphysema.

Use of alpha-lactalbumin: Nutritionally more balanced product for human babies than natural cow-milk.

2.   Bt cotton is an insect resistant plant that contains gene from a bacterium. Name that bacterium and gene. (2)

ü Answer:

Name of bacterium: Bacillus thuringiensis.

Name of gene: Cry gene.

2019 MARCH


1.   Many countries encourage the cultivation of Genetically Modified Crops (G. M. Plants). Write any two advantages of GM plants. (2)

ü Answer:

GM plants are

a.   Tolerant to abiotic stresses.

b.   Pest resistant

2.   PCR and ELISA are two molecular diagnostic techniques. (2)

a.   How is PCR useful in molecular diagnosis?

b.   What is the principle of ELISA?

ü Answer:

(a) PCR is useful for early detection of diseases, gene mutation, cancer etc.

(b) It is based on the antigen – antibody interaction.


2018 SAY June


1.   Match the Column A with Column B. (2)

Column A

Column B

(a) Human Alpha lactalbumin

(1) ELISA

(b) Antigen Antibody Interaction

(2) ELI LILLY

(c) Genetically engineered Insulin

(3) CORN BORER

(d) Cry I Ab

(4) ROSIE

 

(5) BOLL WORM

ü Answer:

Column A

Column B

(a) Human Alpha lactalbumin

(4) ROSIE

(b) Antigen Antibody Interaction

(1) ELISA

(c) Genetically engineered Insulin

(2) ELI LILLY

(d) Cry I Ab

(3) CORN BORER


2.   Bt cotton is a transgenic pest resistant plant. (3)

a.   How this was achieved?

b.   How does this plant survive on pest attack?

ü Answer:

(a) Bt toxin gene is isolated from Bacillus thuringiensis and incorporated into cotton plant to form Bt cotton.

(b) When an insect ingests the toxin in Bt cotton, it becomes active. Toxin binds to surface of mid-gut epithelial cells creating pores. It causes cell swelling and lysis and death of the insect.


2018 MARCH

1.   Genetically modified plants have been used in many ways. Give any four advantages of such plants. (2)

ü Answer:

Ÿ Tolerant to abiotic stresses.

Ÿ Reduced use of chemical pesticides.

Ÿ Pest resistant crops.

Ÿ Reduce post-harvest losses

Ÿ Enhanced nutrient value of food.

2.   In 1983, American company Eli Lilly produced human insulin artificially. Write down the method followed in this technique. (2)

ü Answer:

They prepared two DNA sequences corresponding to A & B chains of human insulin and introduced in plasmids of E. coli to produce insulin chains. Chains A & B were combined by creating disulfide bonds to form human insulin.

3.   Meloideqyne incognitia is a nematode parasite infects the root of tobacco plants. its infection can be prevented by biotechnological methods. (3)

a.  Name the strategy.

b.  Explain the principle behind this strategy.

ü Answer:

(a) RNA interference (RNAi).

(b) Nematode specific genes were introduced into the host plant through the Agrobacterium vector.

This gene produces both sense and antisense RNA in host cells.

These are complementary to each other and form dsRNA.

dsRNA silences the specific mRNA of the nematode.


No comments:

Post a Comment