5.7.1 Draw diagrams of the adult male and female reproductive systems.

• Diagrams will be inserted at a later date.

5.7.2 Explain the role of hormones in regulating the changes of puberty (testosterone, estrogen) in boys and girls, and in the menstrual cycle (follicle stimulation hormone (FSH), luteinizing hormone (LH), estrogen, and progesterone).

• From birth to the age of ten, testosterone level is very low. It increases sharply after that and begins puberty in males. This is when sperm production takes place. Testosterone stays at high levels until the age of 40-50, then it gradually decreases. It is also responsible for voice change, hair growth in certain parts of the body, and the building of muscles. Estrogen leads to the production of eggs, which leads to the menstrual cycle. In the menstrual cycle, FSH is secreted by pituitary increases, this is responsible for the growth of an oocyte (an immature egg) and it's follicle. Two weeks after the start of menstruation, ovulation occurs due to a sudden and sharp increase in LH from the pituitary gland. It also causes the empty follicle to develop into the yellow body which starts releasing the hormone progesterone. This is responsible for maintaining and thickening the endometrium(wall of the uterus) in preparation for implantation.

5.7.3 List the secondary sexual characteristics in both sexes.

• Secondary sexual characteristics in males are the growth of hair in certain parts of the body, change in voice, and building of muscles. In females, it is the growth of hair in certain places and the beginning of the menstrual cycle.

9.1.1 Draw the structure of testis tissue as seen using a light microscope.

• The drawing will be inserted at a later date.

9.1.2 Outline the processes involved in spermatogenesis including mitosis, cell growth, the two divisions of meiosis and cell differentiation.

• Spermatogonia, diploid cells, go through mitosis first many times. This creates large populations of potential sperm (at this time they are still diploid, as they have undergone mitosis only). If the animal were to have a diploid number of 4, in the first division of meiosis, the chromosome number of these potential sperm cells is reduced by half. These spermocyte chromosomes are then duplicated, consisting of two identical chromatids. The second meiotic division produces four spermatids, each with two single chromosomes. Spermatids then differentiate into mature spermatozoa, or sperm cell.

9.1.3 Outline the origin and the role of the hormones FSH, testosterone, and LH in spermotogenesis.

• FSH periodically stimulates a follicle to begin growing again and induces its primary oocyte to begin the second meiotic divisions in females. In males, however, it serves another function. The increased release of FSH combined with LH from the anterior pituitary glands in the head induces the increased production of testosterone, which in turn increases the rate of spermatogenesis. LH stimulates androgen production by the interstitial cells and androgen is required for sperm production. Androgen is a type of testosterone, which again increases rate of spermatogenesis.

9.1.4 Draw the structure of the ovary as seen using a light microscope.

• The drawing will be inserted at a later date.

9.1.5 Outline the processes involved in oogenesis including mitosis, cell growth, the two divisions of meiosis, the unequal division of cytoplasm and the degeneration of polar bodies.

• Ova is produced by mitosis producing diploid oogonia. Each oogonia develops into a primary oocyte, which is also diploid. Typically each month, an oocyte completes meiosis I. The meiotic divisions in oogenesis involve unequal cytokinesis. The first division produces a large cell and a much smaller polar body. The second meiotic division, which produces the ovum and a smaller polar body, occurs only if the sperm cell penetrates the secondary oocyte (at this time the second polar body also divides, yielding three polar bodies in total). After meiosis is completed and the second polar body separates from the ovum, the haploid nuclei of the sperm and the mature ovum, haploid at last from the final division, fuse together in the actual process of fertilization. After fertilization the three polar bodies degenerate and rapidly die.

9.1.6 Draw the structure of a mature sperm and egg.

• The drawing will be inserted at a later date.

9.1.7 Outline the role of the epididymis, seminal vesicle and prostate gland in the production of semen.

• The epididymis is where the sperms move to in order to travel out of the body. The seminal vesicles are in the ejaculated semen and they release a sugary solution to feed the sperm for their long swim towards the egg. The prostate gland releases the alkaline solution that constitutes the seminal fluid. This fluid provides proper environment and nutrition for the sperm cells before, while and after they are ejaculated.

9.1.8 Compare the processes of spermatogenesis and oogenesis including the number of gametes and the timing of the formation and release of gametes.

• Spermatogenesis begins between ages 12-14. About 900 sperm gametes ejaculate and sperms are produced continuously under the effect of a certain level of testosterone in the blood. In meiosis, 4 equally-sized sperm are formed. Males start producing sperm around the age of 14. Around ages 20 to 40, maximum numbers of sperm are produced. It then starts to decline gradually but doesn't stop completely. Oogenesis begins between the ages of 10 and 14. Usually one gamete is produced per menstrual cycle (28 days). One large egg and 3 small polar bodies are produced in meiosis. Only one egg is used in fertilization. The polar bodies are discarded and they die. Females produce eggs from about the age of 13 to about the age of 50. At this age, menopause sets in and no more eggs are produced.

9.2.1 Describe the process of fertilization including the acrosome reaction, penetration of the egg membrane by a sperm and the cortical reaction.

• The acrosome reaction is when the sperm comes into contact with the coats surrounding the egg, and as the contact takes place the acrosome (an enzyme-filled vacuole at the tip of the sperm) bursts open and releases enzymes that digest the jelly coat of the egg. The sperm membrane then comes in contact with the egg cell membrane and the two membranes fuse, followed by the entry of the sperm nucleus into the cytoplasm of the egg. The cortical reaction results as the sperm comes in contact with the egg cell membrane, triggering changes to the egg cell membrane making it impossible for other sperms to enter.

5.7.4 State the difference between copulation and fertilization.

• Copulation is the physical contact between the male and female reproductive structures that is needed for the sperms to move from the male to the female but does not necessarily result in fertilization due to the use of a contraceptive or being infertile. Fertilization is the fusion of the male and female nuclei to produce the zygote.

5.7.5 Describe early embryo development up to the implantation of the blastocyst.

• Fertilization occurs and results in the formation of the zygote which starts a series of cell divisions. (dividing process=cleavage). Cleavage continues, with the embryo becoming a ball of cells by the time is reaches the uterus about 3 to 4 days after fertilization. by about 1 week after fertilization, cleavage has produced an embryonic stage called the blastocyst. During the next 5 days, the blastocyst implants into the endometrium.

9.2.2 Outline the role of human chorionic gonadotrophin (HCG) in early pregnancy

• Human chorionic gonadotropin is an embryonic hormone that acts like pituitary LH to maintain secretion of progesterone and estrogens by the curpos luteum through the first trimester. In the absence of hormonal override, the decline in maternal LH due to inhibition of the pituitary by progesterone would result in menstruation and spontaneous abortion of the embryo. Levels of HCG in the maternal blood are so high that some is excreted in the urine, where it can be detected in pregnancy tests.

9.2.3 Describe the structure and functions of the placenta including its hormonal role in the maintenance of pregnancy (secretion of estrogen and progesterone).

• During first 2 to 4 weeks of development the embryo obtains nutrients directly from the endometrium. However, tissues grow out from the developing embryo and mingle with the endometrium and form the placenta. The placenta is disk-shaped and grows to about the size of a dinner plate weighing less than 1 kg. Diffusion of material between the maternal and embryonic circulations provides nutrients, exchanges respiratory gases, and disposes of metabolic wastes for the embryo. Blood from the embryo travels to the placenta through arteries of the umbilical cord and returns via the umbilical vein, passing through the liver of the embryo. The embryo secretes hormones that signal its presence and control the mother's reproductive system (such as HCG, mentioned above). HCG acts like pituitary LH to maintain secretion of progesterone and estrogens by the corpus luteum through the first trimester. In the absence of this hormonal override, the decline in maternal LH due to inhibition of the pituitary by progesterone would result in menstruation and spontaneous abortion of the embryo.

5.7.6 State that the fetus is supported and protected by the amniotic sac and amniotic fluid.

• The fetus is supported and protected by the amniotic sac and amniotic fluid.

5.7.7 State that materials are exchanged between the maternal and fetal blood in the placenta.

• Materials are exchanged between the maternal and fetal blood in the placenta.

5.7.8 Outline the process of birth and its hormonal control, including progesterone and oxytocin.

• Labor, delivery and afterbirth mark the three stages of birth. Labor is marked by contractions of the uterus, it is stimulated by a hormone called oxytocin, which is released by the pituitary gland. Dilation of the cervix also occurs at this time. Later, the cervix becomes fully dilated. The most powerful contractions are during the next stage, delivery. Placenta, along with other fluids and blood come out after the baby. This placenta that comes out marks the afterbirth. Labor and delivery are controlled by the actions of oxytocin, progeterone, and oestrogen.

5.7.9 Describe four methods of family planning and contraception.

• There is sterilization. In this, the female gets a tube legation where the oviducts are tied so the sperm can't reach the egg, or the male gets a vasectomy where the sperm ducts are cut and prevents the release of sperm. Another method is pills. These prevent ovulation by inhibiting FSH and LH. The use of a male condom prevents the release of sperm into vagina. Another method is intrauterine device (IUD) which prevents fertilization or implantation. A behavioral form of contraception is to, of course, not have sex.

5.7.10 Discuss the ethical issues of family planning and contraception.

• Some people believe it is unethical to abort a baby; that is to kill a fetus that was formed after fertilization. Other people think it is the right of the woman carrying the fetus to decide what to do with it. Some people, such as Mormons, believe that it is right to produce as many children as possible. Thus, for them any type of family planning is unethical.

5.7.11 Outline the technique of amniocentesis.

• Amniocentesis is where some amniotic fluid is drawn by a syringe through the abdomen of the mother. The cells are then grown on a tissue culture to be studied to create a karyotype and are then studied to find out if the are any abnormalities.

5.7.12 Outline the process of in vitro fertilization (IVF).

• Eggs are removed from the ovaries of a woman by suction through the vagina. They are sucked into a syringe and placed in a glass dish. The eggs are then cleaned to remove blood and other unwanted material. The egg is then incubated. Then, sperms are added and fertilization takes places and the embryo is then transferred through the vagina to the uterus.

5.7.13 Discuss the ethical issues of IVF.

• This is, of course, an artificial process. If one believes that those who cannot have children are meant not to have children, one would not support IVF. In addition, IVF often includes the fertilization of many eggs in order to insure that one will produce a healthy baby. The other zygotes, however, are often thrown away, which is a form of abortion. If one believes abortion is wrong, then one would have to deliver all the babies that are produced via a test tube. This is why mothers who do IVF often have many children in one delivery