Please help me with this, they want very detailed answers and its not from our t

Question

Please help me with this, they want very detailed answers and its not from our textbook so I'm lost. Thank you so much.

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Instructions: Students are required to provide detailed answers to each question. Answers should should demonstrate comprehension of the material and should not be vauge.

QUESTION #3 [10 pts] Mitosis and meiosis are both processes of cell division involved in reproduction. The following questions compare and contrast meiosis with mitosis. (For Parts A D only) a) The ploidy of daughter cells as a result of meiosis is different than that of the parental cell. Briefly explain what this statement means. Specify what phase during meiosis this change occurs. [2 pts] b) Just as in mitosis, cohesin is an important protein that keeps chromatids together during meiosis and is similarly targeted by separase as well. In the context of meiosis, however, there are multiple variants of cohesin with different qatnry structures. Why do you think this is necessary? [2 pts] c) Homologous recombination is a unique feature of meiosis whose purpose is to increase genetic diversity during reproduction. What does the process of homologous recombination entail, and how does this process achieve the purpose of increasing diversity? When does homologous recombination occur? [2 pts] d) Define independent assortment within the framework of meiosis. What impact does homologous recombination have on the principle of independent assortment? [3 pts]

Explanation / Answer

a) Ploidy is defined as the number of sets of chromosomes present in a cell, or in the cell of an organism.

Each and every cell in the human body are diploid(contains 2 sets of chromosomes), except gametes which are haploid(contains only one set of the chromosomes) since each gamete from both the parents contribute to the formation offspring who is diploid.

This process of formation of gametes is brought about by meiosis. Hence, the ploidy of the daughter cell(gamete) as a result of meiosis is different than that of parental cells.

Change in the ploidy of daughter cells during meiosis takes place in the Telophase of cell division.

b) Cohesin is a molecule which helps in the cohesion of sister chromatids during the process of cell division in both meiosis and mitosis. There are different variants of cohesin in meiosis as compared to mitosis due to the presence of an important step in meiosis which is absent in mitosis known as Crossing over by chiasma formation during late pachytene stage of prophase 1.

Crossing over is the process which helps in the mixing of genetic material between non-sister chromatids of homologous chromosomes. It takes place by chiasma formation which is brought about by cohesin. Hence, there are multiple variants of cohesin with different quaternary structures seen in meiosis as compared to mitosis.

c) Homologous recombination allows a more independent segregation between the two alleles that occupy the positions of single genes on a chromosome, as recombination mixes the allele content between the homologous chromosomes. crossing over helps in the rearrangement of maternal and paternal alleles on the same chromosomes. Therefore, if two alleles appear together in one offspring does not have any influence on the probability that another offspring will have the same combination of alleles which helps in the formation of different phenotypes and achieves the purpose of increasing diversity.

Homologous recombination occurs during the pachytene stage of the prophase of the first meiotic division.

d)The Law of Independent Assortment is a principle of inheritance that states that each heritable allele is inherited independently from one another. It is one of the three principles put forth by Gregor Mendel and are together known as Mendelian Laws of inheritance.

Homologous recombination prevents the segregation of alleles present on the same chromosome so that they are inherited independently. Therefore homologous recombination actually helps in following the law of Independent Assortment.

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