meiosis

meiosis

a specialised form of cell division that occurs in sexually reproducing organisms and is used to produce the gametes necessary for sexual reproduction.

meiosis 1

separates each homologous chromosome into two different cells

meiosis 2

separates each sister chromatid into four different cells

interphase

cell grows and duplicates all of its chromosomes in preparation for division.

prophase 1

nuclear membrane breaks down as chromosomes condense and line up in homologous pairs for crossing over

metaphase 1

Homologous chromosomes line up randomly on opposite sides of the metaphase plate, with one copy (paternal or maternal) on either side.

Each chromosome attached to the microtubules in preparation to be separated.

anaphase 1

homologous chromosomes are moved apart towards opposite poles of the cell

sister chromatids remain attached to one another at the centromere

telophase 1

chromosomes arrive at opposite ends of the cell as the nuclear membrane is cleaved.

A cleavage furrow forms in preparation for the cell to undergo cytokinesis.

prophase 2

nuclear envelope begins to break down

chromosomes condense

spindle fibres form in preparation to pull apart the sister chromatids of each chromosome.

metaphase 2

chromosome lines up along the metaphase plate of the cell

microtubules from opposite poles of the cell prepare to pull the chromosomes apart.

anaphase 2

sister chromatids separated, pulled towards opposite poles of the cell by microtubules, which are attached at each centromere and become

telophase 2

individual chromatids now at each pole of the cell

separate nuclear membranes begin to form around each set as the chromosomes begin to decondense and unravel

cytokinesis

splits each of the chromosome sets at opposite ends of the cell into four new, individual cells. The resulting daughter cells are haploid.