MCAT Biology : Oogenesis and Spermatogenesis
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Example Question #1 : Oogenesis And Spermatogenesis
What is a key difference between spermatogenesis and oogenesis?
Spermatogenesis results in only 1 sperm; oogenesis results in 2 eggs.
Spermatogenesis results in 4 sperm; oogenesis results in only 1 egg.
Spermatogenesis results in 8 sperm; oogenesis results in only 4 eggs.
Spermatogenesis results in only 1 sperm; oogenesis results in 4 eggs.
Spermatogenesis results in 2 sperm; oogenesis results in only 1 egg.
Spermatogenesis results in 4 sperm; oogenesis results in only 1 egg.
During spermatogenesis, one spermatogonia will become 4 separate functioning spermatozoa. In oogenesis, a primary oocyte will become 1 functioning ovum (or egg) while 3 polar bodies are also produced, which are nonfunctioning and never become eggs.
Example Question #81 : Animal Biology
When a female ovulates, in what phase of division is the oocyte?
Metaphase II
Metaphase I
Prophase II
Prophase I
Anaphase I
Metaphase II
When a female ovulates, the oocyte is in metaphase II, until it becomes fertilized by a sperm. It then completes the second phase of meiosis to make a mature ovum. Remember that, unlike spermatogenesis, oogenesis begins during development. All oocytes undergo meiosis I during fetal development, and are kept suspended in prophase II until ovulation, when they shift to metaphase II. Meiosis only continues beyond metapahse II if fertilization occurs.
Example Question #1 : Oogenesis And Spermatogenesis
How long does spermatogenesis take in adult humans?
7 months
2 weeks
25 weeks
64 days
72 hours
64 days
Spermatogenesis takes approximately 64 days in adult humans. Males begin producing sperm at puberty, and continue until death.
Example Question #13 : Reproductive System And Development
What is the "Dictyate state?"
Pre-vitellegenic stage in fetal development
A meiosis stabilizing factor
The state between fertilization and the start of gonadotropin production
An oogenetic ‘stasis’ between embryo and puberty
The primordial follicle
An oogenetic ‘stasis’ between embryo and puberty
Oogenisis halts in the female embryo while the oocytes are trapped in meiosis II. At the beginning of the menstrual cycle a number of oocytes in primordial follicles are stimulated by pituitary gonadotropins to continue maturation.
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