Flowering plant life cycle

1.  An anther has two pollen sacs with diploid cells that give rise to microspores.

2. Meiosis produces microspores.

3. Microspores develop into pollen grains (male gametophytes).

4. An ovule forms on the ovary wall. It contains a diploid cell that will undergo meiosis.

5. Meiosis produces megaspores.

6. A megaspore develops into a female gametophyte;that includes an egg and six other cells, including a cell with two nuclei.

7. Pollinationoccurs, and the pollen grain germinates.A pollen tube grows to and through ovary tissue to the ovule,where it releases two sperm.

8. During double fertilization, one sperm fertilizes the egg to form a zygote; the other fertilizes the cell with two nuclei to form a triploid (3n) cell.

9. The ovule develops into a seed.