Biology, asked by GKSGOUTAM8928, 6 months ago

. A dividing cell with 439 chromosomes will have how many chromatids during prophase of Meiosis 1, Meiosis 2 and Mitosis. Do you think gamete formation of that individual leads to some sterile gametes, if yes kindly explain?

Answers

Answered by aadi6152
2

Answer:

5.1   Meiosis Defined

Meiosis creates gametes (egg and sperm cells).

During meiosis, genetic information is exchanged between the maternally and paternally inherited copies of a pair of chromosomes in order to create new combinations of genes. This process of genetic recombination helps to increase genetic variability within a species. It allows for the transmission of virtually limitless combinations of genes from parent to offspring.

The resulting gametes have 23 new chromosomes, one member of each of the 23 pairs, representing unique combinations of the original maternal and paternal copies.

5.2   Meiosis Terminology—Homolog

Homologous chromosomes, or homologs, consist of the members of any given chromosome pair. One member of the homolog is the chromosome from the mother and the other member is from the father.

During meiosis, homologs pair together.

5.3   Meiosis Terminology—Chromatid

A chromatid is formed during meiosis and is one of two identical DNA strands formed after DNA synthesis.

Sister chromatids are from the same chromosome, and they are connected together at the centromere.

The classic drawing of a chromosome shaped like the letter X actually depicts sister chromatids.

Click here to see an animation of the steps of meiosis I

5.4   The Two Parts of Meiosis—Meiosis I

Meiosis is divided into two parts: meiosis I and meiosis II.

In meiosis I, each chromosome in a cell is replicated to yield duplicated sister chromatides for each member of the homologous chromosomes.

Physical contact between chromatids may occur, resulting in the formation of chiasmata (from the Greek khiasma: to cross).

Chiasmata are thought to represent the process of crossing over, or recombination, in which an exchange of DNA between two of the four chromatids occurs.

A chiasma occurs at least once per chromosome pair. Thus, a parental haplotype (the arrangement of many alleles along a chromosome) will not remain intact upon transmission to an offspring but, instead, will become a new combination of the original maternal and paternal haplotypes.

Following the process of crossing over, at least two of the four chromatids become unique, or unlike those of the parent.

on of maternally and paternally derived chromosomes in the progeny cells.

Each chromosome moves independently of all the others – a phenomenon called independent assortment. For example, the copy of chromosome 1 that a gamete receives in no way influences if the same gamete will receive the maternally-derived or paternally-derived chromosome 4.

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