When prophase I occurs the chromosomal condensation enables the chromosomes to be looked at under the microscope. Then during late prophase I the homologous chromosomes laterally pair or usually side by side which is then known to be in synapsis this is when cross connections form from Breakage and re-joining between the chromatids which can occur between the pair homologous chromosomes which then lead to genetic combination between the strands which are there. Chiasma occurs which is the point where a crossover occurs http://cyberbridge.mcb.harvard.edu/mitosis_6.html Metaphase 1 of meiosis
During metaphase 1 every pair of bivalents (two chromosomes, four chromatids total) are put in line on the metaphase plate. This is a different mitosis metaphase, which is where all the chromosome are in a single file on the metaphase plate. The position are random. So basically the parental homolog appears on every side. Which means there is a possibility of a 50-50 chance for the daughter cells to get either the mother's or father's homolog for every chromosome. http://cyberbridge.mcb.harvard.edu/mitosis_6.html Further genetic variation comes from crossing over, which may occur during prophase I of meiosis.
http://www.phschool.com/science/biology_place/labbench/lab3/crossovr.html
Metaphase 2 of meiosis
In metaphase 2 every daughter cell is completed the formation of a spindle apparatus. So the sigle chromosomes be put in a straight line on the metaphase plate to which it shows the contrast between metaphase 1 where the homologous pairs of chromosomes put in a straight line on the metaphase plate. For every chromosome sister chromatids look at the opposite poles also every single one is attached to a kinetochore microtubule which comes from that pole. http://www.phschool.com/science/biology_place/biocoach/meiosis/metaii.html Fertilisation
When fertilisation occurs 1 gamete from each of the parent joins to form a zygote this is due to the