Feature leading to variations in sexual reproduction
- Reciprocal crossing over of genes between chromatids of homologous chromosomes may occur during prophase I of meiosis. This produces new linkage groups and provides some major sources of the genetic recombination of alleles.
- The orientation of chromatids of homologous chromosomes (bivalents) on the equatorial spindle during metaphase I determine the direction in which the pairs of chromatids move during anaphase I. this orientation is random
- During metaphase II the orientation of a pair of chromatid is also random and determines which chromosome migrate to opposite poles of the cell during anaphase II. These random orientations and subsequent independent assortment (segregation) of chromosomes give rise to a large calculable number of different chromosomes combination in the gametes
- The fusion of male gametes and female gametes to produce diploid gametes is also randomly leading to variation
CATEGORIES General
TAGS Dr. Bbosa Science
