CBSE Class 10 Science 2022 · Paper 31/4/1 · Question 10

After pollination the pollen grain germinates on the stigma: a pollen tube grows out of the pollen grain and travels down through the style to reach the ovary. The male germ-cell passes down inside this tube. In the ovary the tube enters an ovule and releases the male germ-cell there, and it fuses with the female germ-cell (egg) in the ovule. This fusion is fertilisation, and it forms the zygote. Labelled diagram (only the parts concerned): pollen grain on the stigma, pollen tube running down the style, the male germ-cell in the tube, ovary, ovule and the female germ-cell inside the ovule (see the figure).