Biotechnology And Its Applications Ques 9
9. Bacillus thuringiensis forms protein crystals which contain insecticidal protein that [2011M]
(a) binds with epithelial cells of midgut of the insect pest ultimately killing it
(b) is coded by several genes including the gene cry1
(c) is activated by acid pH of the foregut of the insect pest.
(d) does not kill the carrier bacterium which is itself resistant to this toxin
Show Answer
Answer: a
Hints & Solutions
(a) Bacillus thuringiensis produces a large amount of crystalline protein during sporulation. In the cell, toxins are formed along with the spore and are referred to as parasporal body. The bacteria are not capable of entering the insect’s blood and using the host insect to reproduce. The proteins from ingested spores are activated by gut low $pH$ and the polypeptide toxins destroy gut epithelial cells and kill the pest.
BETA
