Step 1 trace the development of the male gamete Procedure 1

Procedure 1 Time to Trace In this exercise, you will trace the male and female gametes from their production in the gonads to the point at which they meet in the uterine tube, where fertilization takes place. Step 1: Male Gamete Trace the male gamete from its earliest stage--the spermatogonium in the seminiferous tubule--through the stages of spermatogenesis to a mature sperm, and then through the male reproductive tract until it exits the body and enters the uterine tube of the female reproductive tract. Trace the pathway using Figure 16.14, and also fill in the space below. Start: spermatogonium FIGURE 16.14 Male reproductive tract End: Uterine tube 16 Reproductive systems I UNIT 16 I 419

Solution

1: The germ cells of seminiferous tubules present near the capsule serve as spermatogonia which divide and produce more cells by mitosis. Some of these new cells serve as primary spermatocytes that undergo meiosis; meiosis I produces two secondary spermatocytes (n) which is followed by meiosis II that produces four spermatids. The spermatids enter the epidydimis where they are stored and capacitated. Vas deferens serves to transports mature sperm to the urethra in preparation for ejaculation. Urethra serves to ejaculalte the semen during intercourse (prostetic urethra--> membranous urethra-->penial urethra--> external urethral meatus)
2: During foetal development, few germinal cells in ovary differentiate and divide mitotically to produce oogonia which in turn divide to produce diploid primary oocyte. In follicular prenatal phase, the primary oocytes start first meiotic division but are transitionally suspended into prophase stage of meiosis I. After puberty, primary oocyte resumes the division and completion of first meiotic division produce one secondary oocyte and one polar body. The secondary oocyte is released from ovary to fallopian tube where it fuses with sperm and completes the meiosis II. If fertilization does not occur, the degeneration of corpus luteum cause menstruation and the secondary oocyte is expelled out through vag alog with endometrium of uterus. (ovary--> fallopian tube-->uterus--> vag).