Cytogenetics Notes

Mitosis 1 meiosis and production of gametes net

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: vs. Mitosis #1 Meiosis and Production of Gametes • Net result: one diploid cell divides into four haploid cells with recombined chromosomes • One round of DNA replication, two rounds of cell division Mendelian Segregation Source: Hartwell Meiosis vs. Mitosis #2 Homologous chromosomes (not sister chromatids) separate at the first meiotic division. Sorting of homologous chromosomes occurs without regard to maternal vs. paternal origin of the chromosomes. Mendelian Independent Assortment Source: Hartwell Meiosis vs. Mitosis #3 • Association of homologous chromosomes to form meiotic tetrad • Recombination (crossing over) Source: Hartwell Gametogenesis • Gametogenesis = meiosis? Human Spermatogenesis Source: Hartwell Gametogenesis Human Oogenesis Source: Hartwell Implications of Meiosis and Gametogenesis #1 Meiosis and the resulting Mendelian segregation ratios are arguably the most impressive example of control and “fairness” observed in biology. Each allele has a 50:50 shot of making it into a given gamete. But nothing’s immune from cheaters… Source: Hartwell Implications of Meiosis and Gametogenesis #2 Faster rates of genetic change (evolution) through the male lineage. Male-Driven Source: Kong et al. 2012 Nature The number of new mutations in a human child is strongly correlated to the age of their father but not significantly related to the age of their mother. length to the taxo branch length to th their divergence c problematic, howe ferences will be c ences between the rates (e.g., popul rates). This problem the branch length f gion where inheri branch length from ample, for each tax tance for a particul dardized by dividi chondrial DNA by dial region. When chloroplastidial inh then control for tax comparisons. Simi roplastidial DNA c chloroplastidial rat DNA region, such inheritance mode d the standardized d ferent inheritance m FIG. 1.—Gymnosper m phylogeny of families and genera utilized Source: Whittle and Johnston 2002 Mol. Biol. Evol. tution rates are rem in this study according to C...
View Full Document

This document was uploaded on 02/28/2014 for the course BZ 350 at Colorado State.

Ask a homework question - tutors are online