Biotechnology and its Applications

Previous Years' CBSE Board Questions

10.1 Biotechnological Applications in Agriculture

MCQ

'cry genes' that code for insecticidal toxins are present in

1. Cotton bollworms
2. Nematodes
3. Corn borer
4. Bacillus thuringiensis. (2020 C)

V5A (1 mark)

What are cry genes? In which organism are they present? (Al 2017)

1. Write the function of crylAc gene.

(AI 2015C)

SAI (2 marks)

1. List any four ways by which GMOs have been useful for enhanced crop output. (Delhi 2019)
2. Name one toxin gene isolated from B. thuringiensis and its target pest. (2019 C)
3. Why does the toxin produced by B. thuringiensis not kill the Bacillus? (2019 C)
4. Why does Bt toxin not kill the bacterium that produces it, but kill the insect that ingests it? (Delhi 2014) (A
5. What does 'cry' genes in Bacillus thuringiensis code for? State its importance in cotton crop. (Al 2014 C)

SAII (3 marks)

1. On spraying Bacillus thuringiensis on an infected cotton crop field the pests are killed by the toxin, however, the toxin although produced by the bacteria does not affect it. Explain giving reason. (2023) A
2. Write the scientific name of the nematode that infests the tobacco plants and the part that it infests.
3. How is Agrobacterium used to protect tobacco plant from this attack? (2023) R
4. What are cry-proteins? With the help of a suitable example, explain how it acts as a biological pesticide. (2022)
5. When Bacillus thuringiensis enters a certain insect's

body, the insect gets killed, but itself remain

unaffected. Explain how it is possible? (2020)

1. Cotton bollworms enjoy feeding on cotton plants but get killed when feed on Bt cotton plant. Justify the statement. (2020)
2. Many people are apprehensive of accepting GM crops. Give three reasons so as to convince them to use these crops. (2019)

A corn farmer has perennial problem of corn-borer

infestation in his crop. Being environmentally

conscious he does not want to spray insectides.

Suggest solution based on your knowledge of

biotechnology. Write the steps to be carried out to

achieve it. (2019)

Why do lepidopterans die when they feed on Bt

cotton plant? Explain how does it happen.

(Delhi 2017)

1. What is GMO? List any five possible advantages of a GMO to a farmer. (Delhi 2016)
2. One of the major contribution of biotechnology is to develop pest-resistant varieties of cotton plants. Explain how it has been made possible.

(Foreign 2015)

Describe any three potential applications of

genetically modified plants. (AI 2015 C, 2014 C)

LA (5 marks)

(b) Answer the following questions based on

Bt-crops:

Why do farmers prefer to grow Bt cotton crop

than genetically unmodified cotton crops?

1. Name any two insects that are killed by Bt toxin.
2. Explain the mechanism by which Bt toxin kills the insects but not the bacterium which possesses the toxin. (2023) U

There are two different farm lands, one where Bt-

cotton crop was cultivated and the other where non

Bt-cotton crop (indigenous) was cultivated. Farmers

responsible for this experimental cultivation were

free to use the farming practices of their choice.

During the cultivation period, the data was collected

with respect to the amount of pesticide used, water

required for irrigation and at harvesting time, the

crop productivity. Based on the data collected, a bar

graph was plotted which is shown below.

120 Non-Bt Average Bt Average 100

Number/Litres 80 60 40 20

0 Crop productivity Pesticide Irrigation (Tonnes/Ha) (Litres/Ha) (Litres/Ha) Inputs

Answer the following questions:

1. Write your interpretation, with reason, on the basis of the three parameters plotted in the graph.
2. Which one of the crops would you like to cultivate in your farm and why?
3. Which one out of these two crops would a farmer from Rajasthan like to cultivate and why?

(Term II, 2021-22) (Ap)

To save the crop plant from the attack of various insect pests the biotechnologists have developed many pest resistant plants. One such example is Bt corn plant. In this plant 'cry' genes were introduced which produces cryproteins in the plant that has toxic effect on the pest (corn borer). Thus saves the corn plant from the

attack of the corn borer. An experimental field study was conducted by the scientists to see the efficacy of the Bt corn plant against the attack of corn borers. Three different species of corn borers namely 'A', 'B', 'C' were collected and were independently fed on non Bt corn plants and Bt corn plants separately for the same period. The extent of the damage caused to the leaf area of the plant was observed and noted down. With the help of the observations and data collected the following bar graph was plotted. Study the graph and answer the questions that follow.

1. Identify the species of the corn borer that was most successfully controlled by Bt corn plant. Give appropriate reason for your inference.
2. Identify the species of the corn borers which shows least impact of toxin produced by Bt genes.
3. What would be your advise as a Scientist, to the farmers for growing this particular Bt corn variety in the area which is infested by species- 'B' of corn borers?
4. Name one Bt gene that encodes protein in corn plants to control corn borers.

(Term II, 2021-22)

1. (a) Name the insect that attacks cotton crops and causes lot of damage to the crop. How has Bt cotton plant overcome this problem and saved the crop. Explain.
2. Write the role of gene crylAb. (2020) U
3. Explain the application of biotechnology in producing Bt cotton. (Delhi 2015 C)

10.2 Biotechnological Applications in Medicine

MCQ

1. Which one of the following is not the product of transgenic experiments?
2. Pest resistant crop variety
3. High nutritional value in grains
4. Production of insulin by rDNA technique
5. Drought resistant crops (2020) U

VSA (1 mark)

Mention the chemical change that proinsulin

undergoes, to be able to act as mature insulin.

(2018)

Suggest any two possible treatments that can be

given to a patient exhibiting adenosine deaminase

deficiency. (Al 2015)

A boy has been diagnosed with ADA deficiency.

Suggest any one possible treatment. (Delhi 2014 C)

80 Key for Sps. of % of leaf area damaged/mm² 20- 30 - 40 - 10 - 0 Non-Bt Crop Bt Crop corn borers 70

1. A OR
2. В C

28. Why do children cured by enzyme-replacement

therapy for adenosine deaminase deficiency need

periodic treatment? (AI 2015 C)

State the role of C peptide in human insulin.

(Al 2014)