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Q: Much of the physiology associated with the reproductive system involves events that occur at the chemical and cellular levels of structural organization. Understanding diseases and disorders requires a solid foundation and understanding of what "normal" human anatomy and physiology is. a. Discuss the difference between haploid and diploid cells. b. What would you expect to happen if you combined the chromosomes of two diploid cells? c. What would happen to the number of chromosomes in a gamete if meiosis I was eliminated by an environmental toxin? Q: Most men that suffer from cystic fibrosis (CF) have an obstructive type of infertility that blocks the transportation of sperm through the ductus (vas) deferens. The production of sperm cells in the testes may be completely unaffected by CF. Which of the following statements regarding the different cells found in the testicular tissues is incorrectly associated with its location and/or function? A. Seminiferous tubules contain spermatogenic cells that secrete testosterone. B. Seminiferous tubules contain sustentacular cells that produce testicular fluid. C Interstitial cells, found between the seminiferous tubules, secrete testosterone. D. Seminiferous tubules contain spermatogenic cells that produce sperm. Q: Varicocele, a condition in which the pampiniform venous plexus in the spermatic cord become enlarged, can cause non-obstructive infertility in males. This condition impairs the countercurrent heat exchange within the spermatic cord, which elevates the temperature in the scrotum. a. Explain the role of the pampiniform venous plexus in sperm production B. Describe the effects that even a small increase in temperature has on sperm production

Answer 1

Q1)

a)

Haploid cells	Diploid cells
Haploid cells are cells that contain only half number of chromosomes, or n number of chromosomes which means that it has only one complete set of chromosomes. The reproduction of haploid cells occurs by meiosis. That means it divides and give rise to 4 haploid cells. In humans haploid cells are only used in sex cells. Examples are germ cells in male or female called gametes.	Diploid cell are cells containing two complete sets of chromosomes or it has 2n number of chromosomes. Reproduction in diploid cell is by mitosis that makes daughter cells that are exact replicas of parent cells. In humans all other cells otherthan sex cells are diploid. Examples include skin cells,muscle cells called somatic cells.

b)When chromosomes of two diplid cells are combined then it is a division process called Meiosis.In humans we have diploid cells except the gametes or sex cells.During meiosis I there are 4 stages.In prophase I the homologous chromosomes pair together.The 2 sets of sister chromatids exchanges bits of DNA with each other.The during Metaphase all the sister chromatids lines up along the equator of cell.Meiotic spindle fibers attaches to sister chromatids.Next phase is Anaphase II and the sister chromatids are pulled to individual chromosomes by meiotic spindle.During telophase II stage a membrane is formed around each set of chromosomes.Then this results in four cells with half a set of chromosomes caled haploid cells.In males they are sperm cells and in females they are egg cells.Thus combining two diploid cells results in meiosis division and production of 4 haploid cells.

c)
When the Meiosis I is eliminated during the Meiosis cell division then disorders resulting from the change in number of chromosomes occurs and these disorders are called nondisjunction.If Meiosis I is eliminated then it fails to seperate the homologous chromosomes and the result is two gamets that lacks that chromosome and two gametes with two copies of chromosome.Normally each parent gives 23 chromosomes to baby.So total of 46 chromosome.But if Meiosis is eliminated then it leads to an aneuploid gamet and leads to a baby with 45 chromosomes or an extra with 47 chromosomes.