The process of $RNA$ interference is used for the development of pest-resistant plants against . . . . . . .

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

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?

In which of the following plants can hybrid embryos be obtained?

Which variety of rice was patented by a $U.S.$ company even though the highest number of varieties of this rice is found in India?

$A$ tumour-inducing plasmid widely used in the production of transgenic plants is that of: