Meiosis Flashcards
Meiosis
The process of cell division that occurs IN the sex organs and PRODUCES the sex cells/gametes
Interphase 1
DNA is replicated creating two identical chromatids which are joined at the centromere.
Nuclear membrane disappears
Prophase 1
Chromosome have shortened and thickened becoming clearly visible. Pairs of homologous chromosomes line up next to each other. Crossing over occurs.
Meiosis 2
The second stage of Meiosis. No Interphase of Prophase stages occur.
Crossing Over
Parts of the chromosome of non-sister chromatids exchange pieces of information (and therefore alleles). Linked alleles are separated, the point at which they cross over is a CHIASMA
Chiasma
The point at where alleles on non-sister chromatids exchange
Metaphase 1
Homologous chromosomes (tetrads) arrange themselves randomly along the cell equator (Independent assortment). Spindle fibres begin pulling the homologous chromosomes apart.
Anaphase 1
The homologous pairs separate and move towards the cell poles.
Telophase 1
Two new daughter cells form. Each one is genetically unique.
Metaphase 2
Chromosomes line up again in the cell equator of each cell
Metaphase 2
Chromosomes line up again in the cell equator of each cell. Spindle fibres form. Independent assortment occurs.
Anaphase 2
Chromatids separate and move towards the cell poles.
Telophase 2
Cytokinesis occurs. Four new haploid daughter cells are formed. Each of them has a different genetic makeup from the other. The cells are gametes.