Question

During which stage or stages (select all stages that apply) of meiosis does DNA condense into chromosomes? Anaphase I Anaphase II Telophase Prophase II Telophase 11 Metaphase Prophase 1 Metaphase 11

Answer 1

Answer: Prophase 1 and Prophase 2

Meiosis occurs in eukaryotic organisms that reproduce sexually. This process includes reduction of the number of chromosomes in a cell before reproduction. Many organisms package these cells into gametes, such as egg and sperm. The gametes can then meet, during reproduction, and fuse to create a new zygote. Because the number of alleles was reduced during meiosis, the combination of two gametes will yield a zygote with the same number of alleles as the parents. To say it simply, meiosis in humans is a division process that takes us from a diploid cell-one with two sets of chromosomes-to haploid cells-ones with a single set of chromosomes.

Phases of meiosis:

There are two primary stages in which cell division occurs: meiosis 1 and meiosis 2.

Both primary stages have sub-stages of their own. I have mentioned the changes in cells in each stage in a simple way below.

Meiosis 1:

Interphase: Cell grows during G1 phase, copies all of its chromosomes during S phase, and prepares for division during G2 phase.

a)prophase 1: The copied or replicated chromosomes condense and move towards the middle of the cell, nuclear envelop breaks down, the centrioles migrate away from one another and both the nuclear envelope and nucleoli break down.​

b)metaphase 1: Tetrads align and are oriented toward the opposite cell poles.

c)anaphase 1: Chromosomes move to the opposite cell poles but sister chromatids remain together.

d)telophase 1: The spindle fibers continue to move the homologous chromosomes to the poles and by the end of this phase two haploid daughter cells are produced having half number of chromosomes.

Meiosis 2:

a)prophase 2: Chromosomes condense and the nuclear envelope breaks down. The centrosomes move apart, the spindle forms between them, and the spindle microtubules begin to capture chromosomes.

b)metaphase 2: The chromosomes line up individually at the center.

c)anaphase 2: The sister chromatids separate and are pulled towards opposite poles of the cell

d)telophase 2: Nuclear membranes form around each set of chromosomes, and the chromosomes decondense. Cytokinesis splits the chromosome sets into new cells, forming the final products of meiosis: four haploid cells in which each chromosome has just one chromatid.

Hope this will help you.

Regards