MBG 1000 Lecture Notes - Lecture 16: Sister Chromatids, Polyploid, Ploidy

• School: University of Guelph
• Department: Molecular Biology and Genetics
• Course: MBG 1000
• Professor: Georgevander Merwe

Document Summary

Chromosome number variation: many plants and most animal species are diploids, monoploidy: only one set of chromosomes, ants, bees, and wasps have monoploid males. Polyploidy: the more chromosomes something has, the bigger it can grow (such as plants, polyploidy: more than 2 sets of chromosomes, plant kingdom 30-35% of flowering plants are polyploids, animal kingdom polyploidy is rare. Polypoid fruit: many varieties of citrus are polyploidy, many seedless varieties of citrus are triploids or pentaploids, seedless bananas, watermelons, and grapes are triploids, diploid bananas, watermelons, and grapes have seeds, ability to reproduce depends on polyploidy level. In meiosis disjunction happens when: homologous chromosomes move apart in anaphase i, and again, when sister chromatids separate and move away from each other during anaphase ii. Chromosome non- disjunction: failure of homologous chromosomes or sister chromatids to separate properly: defect occurs in anaphase of mitosis or meiosis, leeds to uneven chromosome number in gametes / resulting cells phenomenon known as.