Pt2.. there’s 1 more part to this assignment

Meiosis: Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells.

Name of phase: Description

1. Prophase I: New spindle fiber from around the chromosomes.

2. Anaphase I: Spindle fibers move homologous chromosomes to opposite poles.

3. Telophase II: Nuclear membrane reforms, cytoplasm divides, four daughter cells are formed.

4. Metaphase II: Chromosomes line up along equator; not in homologous pairs.

5. Prophase II : The chromosome becomes visible, the nuclear envelope breaks down, crossing over occurs.

6. Anaphase II: Centromeres divide, chromatids move to opposite poles of the cell.

7. Metaphase I: Homologous chromosomes lineup at the equator.

8. Telophase I: Chromosomes gather at the poles, the cytoplasm divides, two daughter cells are formed.

Table

1. Prophase II

2. Anaphase I

3. Telophase II

4. Metaphase II

5. Prophase I

6. Anaphase II

7. Metaphase I

8. Telophase I

Pictures (from attachment in other question attached here)

1. Anaphase I

2. Anaphase II

3. Prophase I

4. Metaphase I

5. Metaphase II

6. Telophase I

7. Prophase II

8. Telophase II

Explanation:

The phases of meiosis can be remembered using the acronym PMAT

The first stage (during Meiosis I), is called Prophase I. During this phase, the chromosomes condense and become visible and the nuclear envelope breaks down. Homlogous chromosomes pair up and crossing over occurs, meaning they exchange bits of DNA.

Next, Metaphase I occurs, in which the pairs of chromosomes move to the centre (equator) of the cell and line up long the equator.

Anaphase I then occurs, where special microtubules called spindle fibres pull the homologous chromosomes to opposite sides of the cell.

The next step is called Telophase I, in which the chromosomes gather at the poles, spindle fibres degrade, the cytoplasm divides and a new nuclear membrane forms - producing 2 daughter cells.

The cell now enters Meiosis II, the first stage of which is Prophase II. During prophase II, the chromosomes condense, the nuclear envelope breaks down again and a new spindle apparatus forms.

The next stage is Metaphase II, during which the chromosomes (now not in their homologous pairs as these have already been divided) are aligned in the centre of the cell, the equator.

The next stage is Anaphase II, in which the chromatids are pulled to opposite ends of the two daughter cells by the spindle.

The final stage is Telophase II, where 4 haploid daughter cells are formed  after the reformation of the nuclear membranes, division of the cytoplasm and the chromatids uncoil.

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation: