Bt Toxin

Q.

Cry I Ab and cry II Ab produce toxins that control

1. Corn borer and cotton bollworms respectively
2. Tobacco budworms and nematodes respectively
3. Nematodes and tobacco budworms respectively
4. Corn borer and tobacco budworms respectively

Q.

What triggers activation of protoxin to active Bt toxin of Bacillus thuringiensis in bollworm?

1. Body temperature

2. The moist surface of midgut

3. Alkaline pH of gut

4. Acidic pH of the stomach

Q. Cry genes introduced in a plant will not be affective against

1. coleopterans
2. hymenoptera
3. rodents
4. Lepidoptera

Q. In case of Bacillus thuringiensis, Bacillus itself is not killed by the toxic protein crystals produced by it because

1. Bt toxin protein is not produced in the bacillus
2. Bt toxin protein is produced in very less amount in the bacillus
3. Bt toxin exists as inactive toxin
4. Bt toxin can’t cause any damage to bacillus.

Q.

Bt-cotton is a genetically engineered variety of cotton that is resistant to fungal diseases.

1. True
2. False

Q. In Bt cotton, a transgenic plant, Bt is used for the purpose of conferring:

1. High lysine (essential amino acid) content
2. Insect resistance
3. High protein content
4. High vitamin-A content

Q. Insect resistance transgenic cotton has been produced by inserting a piece of DNA from:

1. A bacterium
2. A wild relative of cotton
3. A virus
4. An insect

Q.

Which of the following do not cause disease in plants?

1. Fungi

2. Bacteria

3. Rats

4. Virus

Q. Which was the first commercially grown, genetically engineered crop approved for human consumption?

1. Potato
2. Cotton
3. Maize
4. Tomato

Q. Bt-cotton produces a toxic protein which is encoded by the Cry gene which was obtained from the bacterium __.

Q. Short /Long answer type questions.
What are cry-proteins ? Name an organism that produces it. How has man exploited this protein to his benefit?

Q. Crystals of Bt. toxin produced by some bacteria do not kill the bacteria themselves because

1. Toxin is immature
2. Bacteria enclose the toxin in special sac
3. Toxin is inactive
4. Bacteria are resistant to the toxin

Q.

Which of the following is a correct statement?

1. Somatic hybridization involves fusion of two complete plants carrying desired genes.

2. The anticoagulant hirudin is being produced from transgenic Brassica napus seeds.

3. “Flavr Savr” variety of tomato has enhanced the production of ethylene which improves its taste.

4. “Bt” in “Bt-cotton” indicates that it is a genetically modified organism produced through biotechnology.

Q. Bt toxin is obtained from

1. Bacillus thuringiensis
2. Bacillus subtilis
3. Aspergillus niger
4. Escherichia coli

Q. Why do the toxic insecticidal proteins secreted by Bacillus thuringiensis kill the insect and not the bacteria itself?

Q. What is true about Bt toxin?

1. The activated toxin enters the ovaries of the pest to sterilise it
2. The inactive pro-toxin gets converted into active form in the insect gut.
3. Bt protein exists as active toxin in Baccillus
4. all of these

Q. The prefix “Bt” in Bt cotton means

1. “Barium treated” cotton seeds
2. “Bigger thread” variety of cotton with better tensile strength
3. Carrying an endotoxin gene from Bacillus thuringiensis
4. Produced by “biotechnology” using restriction enzymes and ligases

Q. Lemongrass oil is extracted from

1. Bambusa beecheyana
2. Cymbopogon citratus
3. Cymbopogon martinii
4. Cymbopogon nardus

Q. Assertion :Exotoxins are relased by Gram +ve bacteria causing diseases to animals. Reason: Exotoxins are proteins against whom WBCs react.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
3. Assertion is correct but Reason is incorrect.
4. Assertion is incorrect but Reason is correct.

Q. Cry protein is an insecticidal protein which is produced by

1. Mycobacterium
2. Bacillus thuringiensis
3. Lactobacillus
4. Mycoplasma

Q. Cry I Ab controls infestation of

1. Root pest
2. Corn Borer
3. Stem Borer
4. Cotton Bollworm

Q. Bacillus thuringiensis forms protein crystals which contain insecticidal protein. The incorrect statement about this protein is that it

1. Does not kill the carrier bacterium which is itself resistant to the toxin
2. Binds with epithelial cells of midgut of the insect pest ultimately killing it
3. Is cooked by several genes including the gene cry
4. Is activated by acid pH of the foregut of the insect pest

Q.
Answer the following question:
Name two bacterial diseases of poultry.

Q. The following microbe is used as a biological weapon recently

1. Bacillus anthracis
2. Phytophthora infestans
3. all of these
4. Hibiscus virus

Q. Say that statement is true or false if it is false correct.