The second portion of the chapter deals with muscular fatigue, including the most likely causes of fatigue to various categories of activity, and muscle soreness. Methods of assessing muscular strength are presented in the third section of the chapter.
The sex chromosomes are the X chromosome and the Y chromosome. Sex Chromosomes. In human sexual reproduction, two distinct gametes fuse to form a zygote. Gametes are reproductive cells produced by a type of cell division called meiosis. Gametes are also called sex cells. They contain only one set of chromosomes and are said to be haploid. The male gamete, called the spermatozoan, is relatively motile and usually has a flagellum. The female gamete, called the ovum, is nonmotile and relatively large in comparison to the male gamete.
A regular human sex cell (unless something goes wrong) is haploid (meaning that it has half the chromosomes of a normal body cell). Since normal human body cells have a total of 46 chromosomes (23 pairs), a human sex cell (like sperm) has 23 chromosomes.As there are 23 chromosomes, the sex cells do not have pairs of chromosomes. The fact that sex cells only have half the number of chromosomes as regular cells (no pairs) is a very good thing. regular human sex cell (unless something goes wrong) is haploid (meaning that it has half the chromosomes of a normal body cell). Since normal human body cells have a total of 46 chromosomes (23 pairs), a human sex cell (like sperm) has 23 chromosomes.