Cell Division and Meiosis

Interphase

G1 + S + G2

G1

First Growth

S phase

synthesis.

What happens during S phase?

DNA & Nucleus is replicated.

G2 phase

The cell finishes growing.

Prophase

chromosomes appear, microtubules begin to form, nucleolus disappears.

Methaphase (Middle)

chromosomes line up at the middle.

Anaphase (apart /away)

sister chromatids separate & move to opposite ends of the cell.

Telophase

nuclear envelope appears

cytokinesis

cell is split in two.

Meiosis

reproduction

Diploid

2 copies of each chromosome.

Haploid

1 copy of each chromosome.

Are gametes diploid or haploid?

Haploid.

Prophase I:

crossing over

Methaphase I

homologous chromosomes line up across the center of cell.

Anaphase I

Homologous chromosomes separate & move to opposite ends of the cell.

Telophase I

chromosomes arrive at the poles of the cell.

Anaphase II

sister chromatids separate.

Methaphase II

individual chromosomes line up across the center of cell.

Meiosis I

number of chromosomes is reduced by half

Meiosis II

number of chromosomes does not change