Meiosis

Meiosis
takes place in the germ cells to generate male and female gametes.
to reduce the number of chromosomes to the haploid number of 23 chromosome
Meiosis I:
Similar to mitosis, including the replication of the DNA amount to (2N).
In contrast to mitosis, the homologous chr were paired in meiosis I by a process called synapsis forming 22 pairs of doubled structured chr (except the 2 sex chr). At the final phase of meiosis I each pair of chr will be separated into each of the daughter cells.
Therefore each daughter cell contains haploid 23 doubled structured chr number with N amount of DNA.
Each chromosome shows two cromatids
Crossover
In meiosis I
interchange of segments between the chromatids of a pair of doubled structured chromosome.
The point of interchange is temporarily united, therefore during the separation of the homologus pair in the anaphase of meiosis I an X-like structure is formed called the chiasma formatiom
the interchanged segments break and exchange the positions on the homologus pair after the anaphase.
most frequent between genes that are far apart on a chromosome.
Genetic variability is enhanced through
crossover, which redistributes genetic material
random distribution of homologous chromosomes to the daughter cells.