Role of Bt Bacterium as Biocontrol Agent

Q.

Which of the following can be used as a biocontrol agent in the treatment of plant disease?

1. Lactobacillus

2. Trichoderma

3. Chlorella

4. Anabaena

Q.

What are transgenic plants?

Q. The toxic substance, ‘haemozoin’, related to the high fever and chill, is released during which of the following disease?

1. Dengue
2. Typhoid
3. Malaria
4. Chikungunya

Q. Which of the following is a microbial insecticide?

1. Bacillus subtilis
2. Bacillus thuringiensis
3. Bacillus brevis
4. Bacillus polymixa

Q. Two bacteria found to be very useful in genetic engineering are

1. Nitrobacter and Azotobacter
2. Rhizobium and Diplococcus
3. Nitrosomonas and Klebsiella
4. Escherichia and Agrobacterium

Q.

Which of the following is not used as a biopesticide?

1. Bacillus thuringiensis

2. Xanthomonas campestris

3. Nuclear Polyhedrosis Virus (NPV)

4. Trichoderma harzianum

Q. Cryl endotoxins obtained from Bacillus thuringiensis are effective against:

1. Bollworms
2. Mosquitoes
3. Nematodes
4. Flies

Q. Which of the following statements are true regarding Griffith’s experiment?
I. Biochemical nature of genetic material was known
II. Experimental bacteria were Streptococcus pneumoniae
III. Heat killed virulent bacteria was transformed
IV. S-strain is virulent as it lacks a capsule

1. I & II
2. II & III
3. Only II
4. III & IV

Q.

Bacillus thuringiensis is used as

1. Biofungicide

2. Biopesticide

3. Biocontroller

4. Bioweapon

Q. Name a genus of baculovirus. Why are they considered good biocontrol agents? [2]

Q. The crystals of Bt toxin do not kill the bacteria producing them because

1. The bacteria are resistant to it
2. Toxin itself remains inactive
3. Toxin is immature
4. The toxin is enclosed and secreted out of the cell wall

Q.

Bacillus thuringiensis (Bt) strains have been used for designing novel

1. Bio metallurgical technique

2. Bio mineralisation processes

3. Bio insecticidal plants

4. Bio fertilisers

Q.

The latest trend in plant disease control is

1. chemical control

2. biological control

3. good manure and fertilizer

4. breeding for disease resistance

Q.

What is bioaccumulation?

Q.

What is an example of a transgenic plant?

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

Q. What is Juvenile analogue hormone?

Q.

How do humans use prokaryotes?

Q. Bt-toxins are released as inactive crystals in the bacterial body. What happens to it in the cotton boll worm body that it kills the boll worm ? [1]

Q. Assertion (A): Chemical fertilisers are generally more expensive and hazardous to the environment

Reason (R): Biofertilisers are referred to chemical fertilisers

1. Both the assertion and reason are true and the reason is the correct explanation of the assertion
2. Both the assertion and reason are true but the reason is not the correct explanation of the assertion
3. Assertion is true but the reason is false
4. Both the assertion and reason are false

Q. The Bt toxin is not toxic to human beings because

1. the pro-Bt toxin activation requires a temperature above human body temperature
2. the Bt toxin recognizes only insect-specific targets
3. the Bt toxin formation from pre-Bt toxin requires pH lower than that present in the human stomach
4. conversion of pro-Bt toxin to Bt toxin takes place only in highly alkaline conditions

Q. Devine and collego are

1. Bioinsecticides
2. Biofungicides
3. Bioherbicides
4. Rodenticides

Q. Bt toxin kills insect by

1. Generating excessive heat
2. Creating pores in the midgut epithelial cells, leading to cell swelling and lysis
3. Inhibiting protein synthesis
4. Obstructing a biosynthetic pathway

Q.

Is Actinobacteria harmful?

Q.

Viruses multiply in

1. Dead tissue

2. Living tissue

3. Soil

4. Culture medium

Q. Which of the following bacteria is a comma shaped bacteria?

1. Bacillus clausii
2. Streptococcus pneumoniae
3. Vibrio cholerae
4. Spirillum minus

Q. Statement 1 : Biocontrol refers to the use of biological methods for controlling plant diseases and pests.
Statement 2 : Use of biocontrol measures will greatly reduce our dependence on toxic chemicals and pesticides.

1. Both statements 1 and 2 are correct.
2. Statement 1 is correct but statement 2 is incorrect.
3. Statement 1 is incorrect but statement 2 is correct.
4. Both statements 1 and 2 are incorrect.

Q. (a) Organic farmers prefer biological control of diseases and pests to the use of chemical for the same purpose. Justify.
(b) Give an example of a bacterium, a fungus and an insect that are used as biocontrol agents.

Q. Which of the following statements regarding baculoviruses as biocontrol agents is/are correct ?

1. All of these
2. The majority of baculovirus used as biocontrol agents are included in the genus - Nucleopolyhedrovirus
3. These are important in organic farming because of their specific action on harmful insects without causing any damage to beneficial insects as well as to the environment.
4. Infection with baculoviruses occurs when susceptible hosts (e.g., some specific insects) eat virus particle present on foliage and dies.

Q.

Bacillus thuringiensis is used as

1. Biofungicide

2. Biopesticide

3. Biocontroller

4. Bioweapon