What is the toxic protein produced in $Bacillus \text{ } thuringiensis$ called?

The introduction of $DNA$ into a host cell to make it resistant to nematodes produces ..........

Which part of the tobacco plant is infected by $Meloidogyne \ incognita$?

Insect resistance transgenic cotton has been produced by inserting a piece of $DNA$ from

$A$: Biofortified crops such as golden rice are helpful in overcoming the problem of night blindness in developing nations.
$R$: It has enhanced nutritional content of vitamin $A$.

Crystals of $Bt$ toxin produced by some bacteria do not kill the bacteria themselves because