Meiosis Flashcards
A pair of matching chromosomes in an organism, with one being inherited from each parent.
Homologous chromosomes
When and where does meiosis occur in?
Meiosis occurs in sexual reproduction when a diploid term cell produces 4 haploid daughter cells that can mature to become gametes.
What is the goal of meiosis and why?
To reduce genetic material by half because if genetic content wasn’t reduced, there would be too much.
What is happening during Prophase 1?
Early prophase: chromatids pair. Crossing over occurs.
Late prophase: chromosomes condense. Spindle forms. Nuclear envelope fragments.
The physical exchange of genes between chromatids of homologous chromosomes.
Result: new combinations of genes (alleles)
Crossing over
What happens during metaphase 1?
Chromosomes line up along the equator of the cell.
Key differences in mitosis and meiosis is how chromatids line up.
What happens during anaphase 1?
Chromosomes separate and move to opposite poles. Sister chromatids remain attached to centromeres.
What happens during telophase 1?
Nuclear envelope reassembles. Spindle disappears. Cytokinesis divides cell into two.
What is left at the end of meiosis 1?
Two diploid daughter cells.
What is the result of sister chromatids pulling apart? (Meiosis 2)
4 haploid cells
What happens during prophase 2?
Nuclear envelope breaks down. Spindle forms.
What happens in metaphase 2?
Chromosomes line up along equator of cell
What happens during anaphase 2?
Sister chromatids separate and move to opposite poles.
What happens during telophase 2?
Nuclear envelope assembles. Chromosomes unravel. Spindle disappears. Cytokinesis divides cell into two.
What’re the results of meiosis?
4 haploid cells, one copy of each chromosome.
