DNA replication 1-2
DNA replication
- Mitosis & meiosis
- Mitosis is process of cellular and nuclear division that creates two identical diploid daughter cells.
- Meiosis is production of gametes through one DNA replication and two divisions - cell & nuclear - creating four haploid gametic cells. Not Identical
- Crossover in prophase and metaphase one - of homologous chromosomes - recombination. But haplotype jeans are inherited as a unit as they are closely located. the haplogroups help in studying long term evolution and population histories.
- if non homologous chromosomes exchange segments it is called translocation. In humans translocation is common in 13th and 14th chromosome. Creates infertility. Down syndrome chromosome 21 joins chromosome 14. Also create cancer. non disjunction can be monosomy or trisomy. Rises probability with age 1 out of 1500 if the woman is below 25 and 1/100 at 40 age.Olsen 2003.
- so independent assortment applies to different chromosomes. but not apply to homologous chromosomes.