Page 211 - Canadian BC Science 9

Outcome of Meiosis I Meiosis II Outcome of Meiosis II
Figure 6.6B After meiosis, chromosomes separate and sort themselves into daughter cells.
Gamete formation
Although the process of meiosis is the same for males and females, gamete formation is different (Figure 6.7). In males, meiosis I occurs and produces two cells. It is immediately followed by meiosis II if there are enough nutrients for cell division. The result is four cells with the cytoplasm and organelles equally divided among them. All four cells may develop into mature sperm.
In females, meiosis I occurs and produces two egg cells, but there is an unequal division of the cytoplasm and organelles. Following meiosis II, three of the cells will disintegrate. The remaining one large egg cell retains most of the cytoplasm and is available for fertilization.
Suggested Activities
Conduct an Investigation 6-1C on page 198
Conduct an Investigation 6-1D on page 200
A. Formation of male gametes Meiosis I Meiosis II
B. Formation of female gametes Meiosis I Meiosis II
One haploid egg cell is produced.
Four haploid sperm cells are produced.
Figure 6.7 Meiosis occurs continuously in the testes of human males from puberty. In females, meiosis begins in the ovaries before birth, then stops until puberty and the onset of the menstrual cycle.
Chapter 6 Meiosis is the basis of sexual reproduction. • MHR 193