At ovulation, this secondary oocyte will be released and travel toward the uterus through the oviduct. If the secondary oocyte is fertilized, the cell continues through the meiosis II, producing a second polar body and a fertilized egg containing all 46 chromosomes of a human being, half of them coming from the sperm.
Egg production begins before birth, is arrested during meiosis until puberty, and then individual cells continue through at each menstrual cycle. One egg is produced from each meiotic process, with the extra chromosomes and chromatids going into polar bodies that degenerate and are reabsorbed by the body.
Skip to main content. Reproductive System. Search for:. Gametogenesis Gametogenesis, the production of sperm and eggs, takes place through the process of meiosis.
Spermatogenesis Spermatogenesis, illustrated in Figure 1, occurs in the wall of the seminiferous tubules, with stem cells at the periphery of the tube and the spermatozoa at the lumen of the tube.
Subject optional. Email address: Your name:. Example Question 1 : Understanding Gametogenesis. Possible Answers: During spermatogenesis, the cellular material is divided evenly during meiosis I and II, resulting in four equally sized spermatids.
Correct answer: During spermatogenesis, the cellular material is divided evenly during meiosis I and II, resulting in four equally sized spermatids. Explanation : Spermatogenesis is a continuous process starting at puberty. Report an Error. Possible Answers: Fertilization. Correct answer: Oogenesis. Explanation : The mature human ovum is formed through the developmental process known as oogenesis, which takes place during the first three months of fetal development.
Example Question 3 : Understanding Gametogenesis. Possible Answers: gametogenesis. Correct answer: meiosis. Explanation : During spermatogenesis, spermatogonia become primary spermatocytes, then seconday spermatocytes. Example Question 4 : Understanding Gametogenesis.
Possible Answers: 2. Correct answer: 2. Explanation : During mitosis cells divide a single time and retain the exact same genetic material, producing two identical copies of the parent cell. Example Question 5 : Understanding Gametogenesis. Possible Answers: Somatic cells. Correct answer: The gonads. Explanation : Gametes are the haploid sex cells that are produced in the gonads ovaries in females and testes in males. Example Question 6 : Understanding Gametogenesis.
Possible Answers: a muscle cell. Correct answer: an ovum. Example Question 7 : Understanding Gametogenesis. Which of the following is not a true characteristic of gametocytes? Possible Answers: Gametocytes can divide by mitosis into other gametocytes.
Correct answer: They are eukaryotic somatic cells. Explanation : Gametocytes are eukaryotic germ line cells. Example Question 8 : Understanding Gametogenesis. Possible Answers: The secondary spermatocyte forms during meiosis II and the primary spermatocyte forms during mitosis. The secondary spermatocyte is diploid and the primary spermatocyte is haploid.
The secondary spermatocyte is haploid and the primary spermatocyte is diploid. The primary spermatocyte will undergo meiosis I and become a haploid secondary spermatocyte. This is followed by meiosis II, which generates the haploid spermatids. Finally, these spermatids will migrate to the epididymis, where they mature into spermatozoa i.
The result is 4 sperm produced from a single spermatogonium. Oogenesis, on the other hand, is where things get a bit more complicated. Spermatogenesis begins in the seminiferous tubules and finishes in the epididymis the site of sperm maturation, not shown here.
Sertoli cells are cells which provide nutrients and support for spermatogenesis. While spermatogenesis produces four sperm cells per spermatogonium, oogenesis only results in one egg cell per oogonium. Oogenesis begins with the diploid oogonium which forms during fetal development.
Similar to the spermatogonium, it undergoes DNA replication to become the diploid primary oocyte. Here is an important difference: rather than proceeding immediately to meiosis I, the primary oocyte will actually arrest at prophase I.
This means that females are born with all of the eggs as primary oocytes in prophase I. Meiosis will not proceed until the female gets her first menstrual cycle , at which point one primary oocyte per month will proceed with meiosis. The result of meiosis I is a secondary oocyte and a polar body both haploid. This is another important difference. Rather than producing two viable haploid cells, meiosis I produces only one cell the secondary oocyte that can proceed to meiosis II.
Unlike spermatogenesis that occurs every day, oogenesis occurs once in a month, starting from puberty and ending at menopause. Similar to spermatogonia, the first female reproductive cell is the oogonia, which is a stem cell.
Therefore oogonia have the ability of self-renewal and self-differentiation. Thousands of oogonia divide into around seven million germ cells from the second to the seventh month of embryonic development. The oogonia divide by mitosis to produce the primary oocyte. These primary oocytes undergo meiotic division till the diplotene stage in the embryonic stage, after which it stalls the process of cell division and attains a quiescent stage.
The cell division process is arrested until the girl attains puberty. Some primary oocytes have also been found. Most primary oocytes are destroyed, and around primary oocytes divide into gametes. Upon attaining puberty, the arrestation on the cell division process is lifted, the process continues, and primary oocytes divide into secondary oocytes. However, this division is unequal, and one secondary oocyte and one polar body are formed from a primary oocyte.
The cytoplasm is contained in the secondary oocytes, while the nucleus in the polar body is destroyed. During ovulation, these secondary oocytes are released from the ovary. Spermatogenesis and oogenesis, although taking place in two different individuals, has certain similarities and dissimilarities.
The difference between spermatogenesis and oogenesis are as follows. Production of sperm from spermatogonia. Production of an ovum from oogonia. Testis in males. Ovaries in females. All stages of spermatogenesis take place in the testis. The last stage of oogenesis takes in the oviduct.
Sperms are released from the testis. Ovums are released from the ovary. Rate of production. Millions of sperms are produced every day. One ovum is released once per month.
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