Question 2
What exactly is fertilisation in a flowering plant?
The right answer is the one marked above.
The male gamete within the pollen fusing with the ovule to form a zygote. Two gametes carrying half a set of chromosomes each become one cell carrying a full set.
Pollen being deposited on the stigma is pollination — the two words name different events, and pollination does not guarantee that fertilisation follows. A self-sterile flower is pollinated and never fertilised. The pollen tube growing down the style, and the ovary swelling into a fruit, are the steps either side of it.