What is the purpose of the second meiotic division. 22 Flashcards 2022-10-10
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The second meiotic division, also known as meiosis II, is a crucial stage in the process of sexual reproduction. It follows the first meiotic division, which occurs during the formation of gametes (sex cells) such as eggs and sperm.
The main purpose of the second meiotic division is to halve the chromosome number again, reducing it from diploid (2n) to haploid (n). This is necessary because sexual reproduction involves the fusion of two haploid gametes, one from each parent, to form a zygote with a full complement of chromosomes (2n).
During meiosis II, the chromosomes that were separated during meiosis I are further separated into distinct daughter cells. This occurs through a process known as cytokinesis, in which the cell membrane pinches in to form two separate cells.
The second meiotic division is important because it ensures that each gamete receives the correct number of chromosomes. If this process is not accurate, it can lead to chromosomal abnormalities in the resulting offspring, which can have serious consequences for their development and health.
Overall, the purpose of the second meiotic division is to ensure the proper distribution of chromosomes during sexual reproduction, and to produce genetically diverse offspring that can adapt to changing environments. Without this process, the continuation of life as we know it would not be possible.
When does the second meiotic division take place in the egg?
In second meiosis a N cell is divided into two N cells but this time chromosomes are not doubled in fact N chromatid cells 1. Each pair of centrioles migrate to the opposite pole. A cells of the anterior pituitary that secrete the gonadotropic hormones FSH and LH B cells of the hypothalamus that secrete GnRH gonadotropin-releasing hormone C growth factors for sexual differentiation D hormones of the gonads E cells of the gonads that secrete sex hormones The loss of reproductive capacity that occurs as females age is caused by A altered length of the menstrual cycle. Are gametes formed through mitosis? C Testosterone levels remain elevated throughout adulthood. In a mating involving a deaf man and a deaf woman, could all the children have normal hearing? The chromatids still remain connected by the terminal chiasma and these exist up to the metaphase. Why is it called a secondary oocyte? In contrast to meiosis I, meiosis II resembles a normal mitosis.
Mitosis is conventionally divided into five stages known as prophase, prometaphase, metaphase, anaphase, and telophase. During prophase, the replicated pairs of chromosomes condense and compact themselves. After the karyokinesis in each haploid meiotic cell, the cytokinesis occurs and, thus, four haploid cells are resulted. A stimulation of the first meiotic division only B ovulation only C development of the corpus luteum only D both ovulation and development of the corpus luteum E both ovulation and stimulation of the first meiotic division. ADVERTISEMENTS: The first meiotic division is also known as the heterotypic division.
What Is Division Of The Secondary Oocyte Is Completed?
C acetylcholine-induced myoepithelial cell contraction. In the pachynema stage, this is now changed, the two chromatids of each chromosome containing half of the DNA present in the chromosome at start, become partially independent of one another although they still continue to be linked together by their common centromere. The nucleolus reappears and, thus, two daughter chromosomes are formed. E inhibin stimulates the release of luteinizing hormone LH. Eventually, the secondary oocyte will split again into two separate cells: another small polar body cell and a larger mature cell. B the complete cessation of sex hormone release.
B Fertilization is random. C either a maternal or a paternal sister chromatid. The synapsis begins at one or more points along the length of the homologous chromosomes. At the moment, my thoughts are that the two cell divisions are necessary for recombination to occur, although I am not sure. Independent assortment explains a collection of meiotic products that include gametes of genotype Ab will also include gametes of genotype AB in roughly the same proportion. E have a diminished response to follicle-stimulating hormone FSH. C During gamete formation, allele pairs are separated to form haploid gametes.
B Fertilization is random. Leptotene or Leptonema: In the leptotene stage, the chromosomes become more uncoiled and assume a long thread-like shape. This interphase is not as specific as mitotic interphase; during meiotic interphase, chromosomes may decondense as the cell waits to proceed with meiosis. What is independent assortment? A stimulate mucus secretion to lubricate the cervix and vagina B stimulate uterine contraction and the softening of the cervix so it can dilate C elevate the body temperature D inhibit the inflammatory response as tissue is abraded during delivery E inhibit blood flow through the umbilical cord to prevent excessive bleeding The changes in the uterus that occur during the secretory phase of the uterine cycle are mediated by A decreased estrogen from the adrenal cortex. T he crossing over phenomenon works on the variations of genetic traits among the members of the same species, where it contributes to the genes that carry the genetic traits exchanging between the two homologous Second Meiotic division The second meiotic division aims to increase the number of the produced cells from the first meiotic division, Prophase II, Metaphase II, Anaphase II, And Telophase II are the second meiotic division phases. E a maternal and a paternal sister chromatid. A the maintenance of thickened endometrium B the growth of glandular tissue in the breast C the maintenance of thickened myometrium D the secretion of prolactin E the suppression of contractile activity of uterine smooth muscle cells Which of the following changes in the uterus does NOT occur during the secretory phase of the uterine cycle? The actual reduction occurs at this stage.
B Homologous chromosomes are pulled apart resulting in dyads at each pole. After ovulation the oocyte is arrested in metaphase of meiosis II until fertilization. What is the function of the accessory reproductive organs? The two parental haploid pronuclei then replicate their DNA while migrating towards each other to create their first mitotic division. Perhaps the S phase of interphase triiggers some further stages of cell division such as cytokinesis, and the splitting of the cell will not occur unless some DNA replication has taken place? D increased estrogen from the ovaries. B the corpus luteum degenerates.
What is the importance of second meiotic division?
E oxytocin-induced myoepithelial cell contraction. In meiosis II, the phases are, again, analogous to mitosis: prophase II, metaphase II, anaphase II, and telophase II see figure below. What is the function of androgen-binding protein? They are inderpendent during meiosis B. A Sister chromatids disjoin and are pulled to opposite poles. As before, the smaller polar body cell will eventually deteriorate.
Meiotic cell division (Meiosis) or reduction division stages & features
Metaphase II : During the metaphase II, the chromosomes get arranged on the equator of the spindle. Meiosis II initiates immediately after cytokinesis, usually before the chromosomes have fully decondensed. D are fixed at about 1-2 million at birth with a fraction of that number developing into mature ova. They are immature diploid cells produced in the ovary of the females. A human chorionic gonadotropin hCG : placenta B luteinizing hormone LH : endometrium C luteinizing hormone LH : placenta D human chorionic gonadotropin hCG : endometrium E human chorionic gonadotropin hCG : fetus What is the function of the scrotum? The endoplasmic reticulum forms the nuclear envelope around the chromosomes and the nucleolus reappears due to synthesis of ribosomal RNA rRNA by ribosomal DNA rDNA and also due to accumulation of ribosomal proteins. In the second meiotic division, the haploid cell divides mitotically and results into four haploid cells.
