Introduction | Structures/Functions | Prokaryotes vs. Eukaryotes | Types | Reproduction | Theory | Glossary | Credits

All gametes have half the number of chromosomes that regular cells have. Gametes are created through the process of meiosis. Meiosis involves two divisions which create four haploid cells.

Phase I
INTERPHASE I	PROPHASE I	METAPHASE I	ANAPHASE I	TELOPHASE I
In Phase I, all chromatin material makes a copy of itself. Spindle fibers begin to develop as the nuclear membrane disintegrates. Some crossing over may occur as the chromosomes thicken and group into tetrads. The tetrads line up and pull apart. Once the chromosomes pairs are at opposite poles the cytoplasm material divides. Note how the two cells formed do not have the same genetic material, yet they have the normal number of chromosomes.

Phase II
INTERPHASE II	PROPHASE II	METAPHASE II	ANAPHASE II	TELOPHASE II
In Phase II, no duplication of genetic material occurs. As the chromatin thickens to form chromosomes and group into pairs, the spindle forms and the nuclear membrane disintegrates. As in mitosis, the pairs of chromosomes line up at the center and pull apart to opposite poles. The cytoplams then divides. In male organisms the four new cells are all the same size. In females one of the four cells receives the bulk of the cytoplasm material. This becomes the functioning egg while the other three smaller cells disintegrate.