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

Golden rice is a promising transgenic crop. When released for cultivation,it will help in

By applying which of the following practices,contamination of hydroponics plants can be reduced?

Consider the following statements about $Bt$:
$I.$ The bacteria $Bacillus$ $thuringiensis$ $(Bt)$ are used to control butterfly caterpillars.
$II.$ Fresh spores of $Bt$ are mixed with water and sprayed on crops such as brassicas and fruit trees.
$III.$ Insect larvae,after eating these,are killed by the toxin released in their gut.
$IV.$ $Bt$ toxin genes have been introduced into plants to provide resistance to pests.
Which of the statements given above are correct?

$RNA$ interference,which is employed in making tobacco plants resistant to $Meloidogyne \ incognita$,is essentially involved in:

$A$ transgenic food crop which may help in solving the problem of night blindness in developing countries is