Effects of Bt Toxin on Humans

Q. Which of the following statements regarding baculoviruses are correct?

A. These are species-specific, broad spectrum insecticidal applications.
B. The baculoviruses of the genus Nucleopolyhedrovirus are majorly used as biocontrol agents
C. They have been shown to have no negative impact on target insects
D. These are pathogens that attack insects and other arthropods

1. A, B, C and D
2. A, B and D
3. B and D
4. A and C

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. Which of the following statement is incorrect for the Bt toxin protein?

1. They are encoded by cry genes
2. They are produced in active form
3. They interact with specific receptors located on the host cell surface
4. They are used as insecticides

Q.

How many of the below are examples of physiological barriers?

Acid of the stomach, Skin, Saliva, Mucus membranes, Tears, Interferons

1. 2
2. 5
3. 3
4. 4

Q. Why is Bt toxin not harmful to humans? [2]

Q. Cry protein is obtained from:

1. Bt-gene present in Bacillus subtilis
2. Cry gene present in Bacillus thuringiensis
3. Cry gene present in the Escherichia coli
4. Any bacteria which has a natural plasmid

Q. Physiological barriers include:

1. Acid of the stomach
2. Skin
3. Saliva
4. Mucus membranes
5. Tears

How many of the above are examples of physiological barriers?

1. 2
2. 5
3. 3
4. 6

Q.

Cry proteins are not toxic to humans because:

1. The medium in human gut is basic.

2. Cry proteins are destroyed by saliva.

3. None of the above.

4. The medium in human gut is acidic.

Q. Physiological barriers include:

1. Acid of the stomach
2. Skin
3. Saliva
4. Mucus membranes
5. Tears

How many of the above are examples of physiological barriers?

1. 6
2. 5
3. 3
4. 2

Q. Read the following statements (1 - 4) and select the true (T) and false (F) ones regarding physiological barriers.

1. Lysozyme present in saliva and tears kills viruses by destroying their cell walls.
2. The acid in the stomach destroys bacteria.
3. Lowering body temperature is a natural defence mechanism to destroy pathogens.
4. The sweat and oil secretions make the skin surface pH basic.

1. 1 - F, 2 - T, 3 - F and 4 - F
2. 1 - F, 2 - T, 3 - T and 4 - F
3. 1 - T, 2 - T, 3 - T and 4 - F
4. 1 - F, 2 - F, 3 - T and 4 - F

Q. Toxin produced by Bt cotton plant gets activated in:

1. Mouth of insect by acidic pH
2. Midgut of insect by alkaline pH
3. Leaves of plant by acidic pH
4. Stem of plant by alkaline pH

Q.

Cry proteins are not toxic to humans because:

1. The medium in human gut is acidic.

2. The medium in human gut is basic.

3. Cry proteins are destroyed by saliva.

4. None of the above.

Q. What will happen if you were to consume Bt corn?

1. Autodigestion leading to death
2. B. thuringiensis infection
3. Cry protein will induce stomach cancer
4. Cry protein will be excreted or broken down in the body

Q.

What areCry proteins? Name an organism that produces it. How has manexploited this protein to his benefit?

Q. Why does this nematode die on eating such a GM plant?

Q.

Cry proteins are not toxic to humans because:

1. The medium in human gut is acidic.

2. The medium in human gut is basic.

3. Cry proteins are destroyed by saliva.

4. None of the above.

Q. Physiological barriers include:

1. Acid of the stomach
2. Skin
3. Saliva
4. Mucus membranes
5. Tears

How many of the above are examples of physiological barriers?

1. 2
2. 6
3. 5
4. 3

Q. Physiological barriers include:

1. Acid of the stomach
2. Skin
3. Saliva
4. Mucus membranes
5. Tears

How many of the above are examples of physiological barriers?

1. 2
2. 5
3. 3
4. 6

Q. Select the statement which is not true about Bt toxin

1. Bt toxin can harm humans if consumed
2. Bt toxin is present in the inactive form in the plant and needs alkaline pH to be activated
3. Bt toxin is encoded by Cry gene
4. Bollworm is not the only insect that is killed by Bt toxin

Q. What will happen if you were to consume Bt corn?

1. Cry protein will be excreted or broken down in the body
2. B. thuringiensis infection
3. Autodigestion leading to death
4. Cry protein will induce stomach cancer