Leaves of $Bryophyllum$ fallen on the ground produce new plants. Why?

Distinguish between a gamete and zygote. Explain their roles in sexual reproduction.

Which among the following statements are true for unisexual flowers?
$(i)$ They possess both stamen and pistil.
$(ii)$ They possess either stamen or pistil.
$(iii)$ They exhibit cross-pollination.
$(iv)$ Unisexual flowers possessing only stamens cannot produce fruits.

What are those organisms called which bear both the sex organs in the same individual? Give one example of such an organism.

Every living organism produces another organism like itself. What is this phenomenon called?

Where is $DNA$ found in a cell?