Primordial follicles containing the primary oocyte, arrested at prophase of meiosis I, develop into primary follicle containing cuboidal granulosa cells.
12.
During ovulation, the primary oocyte will resume meiosis in response to signals, arresting in metaphase meiosis II, ready for fertilization.
13.
Thus, an immature ovum can spend up to ~ 55 years as a primary oocyte ( the last ovulation before menopause ).
14.
However, primary oocytes are arrested in prophase 1 of the first meiosis and remain in that arrested stage until puberty begins in the female adult.
15.
For several primary oocytes that complete meiosis I each month, only one or a few functional oocyte, the dominant follicles, completes maturation and undergoes ovulation.
16.
:Okay-first thing to be clear about is that the ovaries do not contain a supply of mature eggs-they contain immature egg cells called primary oocytes.
17.
However, although this process begins at prenatal age, it stops at prophase I . In late fetal life, all oocytes, still primary oocytes, have halted at this stage of development, called the dictyate.
18.
Oogonium ( Oocytogenesis ) > Primary Oocyte ( Meiosis I ) > First Polar Body ( Discarded afterward ) + Secondary oocyte ( Meiosis II ) > Second Polar Body ( Discarded afterward ) + Ovum
19.
Somatic cells, or normal diploid cells of the body, go through mitosis in order to reproduce themselves through cell division, whereas diploid germ cells ( i . e ., primary spermatocytes and primary oocytes ) go through meiosis in order to create haploid gametes ( i . e ., sperm and ova ) for the purpose of sexual reproduction.
20.
In contrast with males, each of the original diploid germ cells or primary oocytes will form only one mature ovum, and three polar bodies which are not capable of fertilization It has long been understood that in females, unlike males, all of the primary oocytes ever found in a female will be created prior to birth, and that the final stages of ova production will then not resume until puberty.
