In which type of plants is the senescent phase not clearly defined?

Select the correct option regarding gamete transfer in sexual reproduction.

Rose plants produce large,attractive bisexual flowers but they seldom produce fruits. On the other hand,a tomato plant produces plenty of fruits though it has small flowers. Analyse the reasons for the failure of fruit formation in roses.

Study the following statements and select the correct option:
$(i)$ Tapetum nourishes the developing pollen grains.
$(ii)$ Hilum represents the junction between the ovule and the funicle.
$(iii)$ In aquatic plants such as Water hyacinth and Water lily,pollination occurs by water.
$(iv)$ The primary endosperm nucleus is haploid.

The chances of hereditary and evolutionary changes are higher in species that reproduce through:

$Statement\; 1$: Zygote is a single cell.
$Statement\; 2$: Two haploid cells fuse to form two diploid cells.