Question

Why fertilisation cannot take place in flowers if pollination does not take place?

Answer 1

For fertilisation to occur in plants male gamete (pollen grains) and female gamete (ovule) should come in contact and this is possible only after pollination. Through pollination the pollen grains reaches the stigma of the flower so that it can penetrate the ovule for fertilisation to occur. So without pollination, fertilisation is not possible.