Bt Crops

Cry-IAc endotoxins obtained from Bacillus thuringiensis are effective against:

1.	mosquitoes	2.	flies
3.	nematodes	4.	bollworms

The bacterium Bacillus thuringiensis is widely used in contemporary biology as a/an:

1. indicator of water pollution

2. insecticide

3. agent for production of dairy products

4. source of industrial enzyme

What is true about Bt toxin?

1.	the inactive protoxin gets converted into active form in the insect gut
2.	Bt protein exists as active toxin in the Bacillus
3.	The activated toxin enters the ovaries of the pest to sterilize it and thus prevent its multiplication
4.	the concerned Bacillus has antitoxins

Some of the characteristics of Bt cotton are:

1.	long fibre and resistance to aphids
2.	medium yield, long fibre, and resistance to beetle pests
3.	high yield and production of toxic protein crystals, which kill dipteran pests
4.	high yield and resistance to bollworms

Which of the following Bt crops is being grown in India by the farmers?

1.	Cotton	2.	Brinjal
3.	Soybean	4.	Maize

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

1. Acidic pH of the stomach

2. Body temperature

3. Moist surface of midgut

4. Alkaline pH of the gut

Given below are two statements:

Statement I:	Bt toxins are insect group specific and coded by a gene cry IAc.
Statement II:	Bt toxin exists as inactive protoxin in B. thuringiensis. However, after ingestion by the insect, the inactive protoxin gets converted into active form due to acidic pH of the insect gut.

In the light of the above statements, choose the correct answer from the options given below:
1. Both Statement I and Statement II are False
2. Statement I is True but Statement II is False
3. Statement I is False but Statement II is True
4. Both Statement I and Statement II are True