Biotechnology and Its Applications Question 20
20. What is true about $B t$ toxin?
[2009]
(a) Bt protein exists as active toxin in the Bacillus
(b) The activated toxin enters the ovaries of the pest to sterilise it and thus prevent its multiplication.
(c) The concerned Bacillus has antitoxins.
(d) The inactive protoxin gets converted into active form in the insect gut.
Show Answer
Answer : d
Hints & Solutions
(d) About $B t$ toxin, it is true, that the inactive protoxin gets converted into active form in the insect gut. There are several advantages in expressing $B t$ toxins in transgenic $B t$ crops. The level of toxin expression can be very high, thus delivering sufficient dosage to the pest. The toxin expression is contained within the plant system and hence only those insects that feed on the crop perish. The toxin expression can be modulated by using tissue-specific promoters and replaces the use of synthetic pesticides in the environment.
