reproduction bio Flashcards
(3 cards)
What is each of the following, and which undergo mitosis during oogenesis?
A.
Zygote
B.
Primary oocyte
C.
Secondary oocyte
D.
Polar body
E.
Oogonia
E. Oogonia are diploid germ cells that divide by mitosis to form primary oocytes. This process takes place during embryonic development before birth and marks the first step of oogenesis.
Process of Elimination
Option A. Zygote – This option is incorrect. A zygote is formed after an ovum gets fertilized by a sperm. It is a diploid cell that undergoes mitosis during fetal development, but not in the process of oogenesis.
Option B. Primary oocyte – This option is incorrect. The primary oocyte is formed when oogonia undergo mitosis and then enter the early stages of meiosis I. This process occurs before birth, after which the primary oocytes are arrested in prophase I until puberty. At puberty, the primary oocytes complete meiosis I, producing a secondary oocyte and the first polar body. The primary oocytes do not undergo mitosis during oogenesis.
Option C. Secondary oocyte – This option is incorrect. The secondary oocyte is produced when the primary oocyte completes meiosis I. It then starts meiosis II but remains arrested in metaphase II unless fertilization occurs. The secondary oocyte does not undergo mitosis.
Option D. Polar body – This option is incorrect. Polar bodies are small, non-functional structures that are a result of uneven cytoplasmic distribution during oocyte meiosis. The polar body may or may not undergo meiosis II, but not mitosis.
acrosome rxn vs capacitation
The acrosome reaction occurs when the sperm reaches the zona pellucida of the oocyte, releasing enzymes from the acrosome that help the sperm penetrate the egg.
Capacitation, however, occurs earlier in the female reproductive tract before the acrosome reaction. Capacitation prepares the sperm by enhancing its motility and making it hyperactive, allowing it to complete the journey to the egg
What is the path of sperm in the male reproductive system?
SEVEn UP to memorize the path of sperm: Seminiferous tubules —> Epididymis —> Vas deferens —> Ejaculatory duct —> Urethra —> Penis (pause before the V for maturation!)
