Level 2 Bio: Meiosis Flashcards
How many stages of Meiosis are there?
Two: Meiosis 1 and Meiosis 2
What is the purpose of Meiosis
The purpose of Meiosis is to produce gametes (sex cells: sperm, egg) which produces genetically different cells with haploid (1/2) the number of chromosomes
What is Meiosis
Cell division that halves the chromosome number so that each daughter cell has one haploid set.
It is Reduction division
Used to form gametes (sex cells (sperm & eggs in animals, pollen & eggs in plants))
What happens in Meiosis
In Meiosis the chromosomes are replicated once but the original cell undergoes 2 cell divisions.
How many daughter cells does Meiosis produce
4 genetically different daughter cells
What controls Meiosis
Enzymes
Do the sister chromatids separate in Meiosis, YES or NO?
NO
In prophase 1 what happens
Homologous chromosomes form a tetrad. When they pair up it’s called synapsis.
The arms of the chromosomes may tangle & form a chiasma.
In Metaphase 1 what happens
Tetrads line up along equator or middle of cell. Independent assortment takes place with Maternal & Paternal chromosomes.
In Anaphase 1 what happens
Centromeres break & homologous chromosomes separate (sister chromatids are still attached). Cytokinesis begins.
In Telophase 1 what happens
Chromosomes may decondense.
Meiosis 1 reaches completion.
In Prophase 2 what happens
Centrioles form & move toward the poles.
Nuclear membrane dissolves
In Metaphase 2 what happens
Microtubules grow from centrioles & attach to the centromeres.
The sister chromatids line up along the cell equator.
In Anaphase 2 what happens
Centromeres break & sister chromatids separate.
Cytokinesis begins.
In Telophase 2 what happens
Chromosomes may decondense (depends on species).
Cytokinesis reaches completion creating Haploid daughter cells.
This creates gametes