Apparatus & Techniques: Looking at Meiosis Under a Microscope

Question 1

How to distinguish meiosis 1 and meiosis 2

Answer 1

Homologous chromosomes pair up side by side in meiosis I only

This means if there are pairs of chromosomes in a diagram or photomicrograph meiosis I must be occurring

The number of cells forming can help distinguish between meiosis I and II

If there are two new cells forming it is meiosis I but if there are four new cells forming it is meiosis II

Question 2

How to see if its prophase 1

metaphase 1

and anaphase 1

Answer 2

Prophase I: Homologous pairs of chromosomes are visible

Metaphase I: Homologous pairs are lined up side by side along the equator of spindle

Anaphase I: Whole chromosomes are being pulled to opposite poles with centromeres intact

Question 3

telophase 1

cytokinesis 1

Answer 3

Telophase I: There are 2 groups of condensed chromosomes around which nuclei membranes are forming

Cytokinesis: Cytoplasm is dividing and cell membrane is pinching inwards to form two cells

Question 4

prophase 2

metaphase 2

anaphase 2

Answer 4

Prophase II: Single whole chromosomes are visible

Metaphase II: Single whole chromosomes are lined up along the equator of the spindle in single file (at 90 degree angle to the old spindle)

Anaphase II: Centromeres divide and chromatids are being pulled to opposite poles

Question 5

telophase 2

cytokinesis 2

Answer 5

Telophase II: Nuclei are forming around the 4 groups of condensed chromosomes

Cytokinesis: Cytoplasm is dividing and four haploid cells are forming

Question 6

For metaphase remember M for the middle of the spindle and cell which is where the chromosomes will be lined up.

For anaphase remember A for away from the middle to the poles, which is where the chromosomes / chromatids are being pulled.