$$ \text { What is self-incompatibility? } $$
It is a genetic mechanism which prevents self-pollen from fertilising the ovules by inhibiting pollen germination or pollen tube growth in the pistil.
$$ \text { Name the type of pollination in self-incompatible plants. } $$
In self-incompatible plants, (while self-pollination is incompatible) cross-pollination is occurs.
Draw the diagram of a mature embryo sac and show its eight-nucleate, seven-celled nature. Show the following parts-antipodals, synergids, egg, central cell, polar nuclei.
$$ \text { A mature embryo sac (seven celled with eight nucleated structure) } $$
Which is the triploid tissue in a fertilised ovule? How is the triploid condition achieved?
Fertilised embryo sac showing Primary endosperm nucleus ( $3 n$ )
$$ \text { Are pollination and fertilisation necessary in apomixis? Give reasons. } $$
Pollination and fertilisation are not necessary for apomixis. The reasons in support of this are given below
(i) Embryo sac can develop from megaspore without reduction division the egg is diploid and develops into embryo.
(ii) Embryo sac can also develop from diploid nucellus cells in which case egg is diploid that develop into embryo parthogenetically.