Question

describe what happens after pollen grain reaches the stigma​

Answer 1

Answer:

when pollen grains reaches stigma then they make use of external agents to achieve pollination

Answer 2

Answer:

When a pollen grain lands on the stigma of a flower of the correct species , a pollen tube begins to grow. It grows through the style until it reaches an ovule inside the ovary. The nucleus of the pollen then passes along the pollen tube and fuses (joins) with the nucleus of the ovule.