From Seed to Seed:
Plant Science for K-8 Educators

Review of the reproductive process

We have already spent quite a bit of time on the different types of cell division. Mitosis, you'll recall, is the type of cell division that results in two daughter cells that are genetically identical to the parent cell. This type of cell division generally occurs in the meristems and is responsible for plant growth.

During meiosis, the other type of cell division, certain diploid cells (cells with paired chromosomes) divide to form four haploid cells. Remember that during meiosis, a cell's genetic material is replicated once but the cell divides twice, resulting in four daughter cells, each with half the number of chromosomes the parent cell has. These haploid cells are the spores. Remember that spores give rise to the gametophyte generation, which, in turn, produces the gametes (egg and sperm).

Sexual reproduction involves the union of these gametes. If fertilization is successful, an egg and sperm fuse to create a zygote and, ultimately, a new plant.

In this section we will be taking a closer look at the union of reproductive cells, focusing on where genes and genetics come into the picture. But first, let's do a little "time traveling."