Mitosis and meiosis Flashcards
What is cytokinesis?
Splitting into 2 daughter cells after mitosis
5 things that happen during prophase
nucleus breaks down chromosome condenses spindle fibers form spindle fibers attach to centromere on chromosomes nucleolus dissolves
What does cohesin do?
it keeps sister chromatids together and facilitates binding of the spindles at the kinecticore to the centromere
also facilitates recombination
How are homologous autosomal chromosomes kept together during propphase 1 of meiosis?
synaptonemal complexes
How are sex chromosomes kept together during prophase 1 of meiosis?
pseudoautosomal regions exist within each chromatid that allows aggregation
What are the 2 ways to create genetic variability in meiosis?
Crossing over in prophase 1 and independant assortment in anaphase 1 and 2
What is the name of the genetic disease where the genotype is 45XO?
Turners syndrome
What cell stage are eggs arrested at till ovulation?
diplotene stage of prophase 1
What cell stage is completed at ovulation?
Meiosis 1 is completed
What stage is completed upon fertilization of an egg by a sperm?
Meiosis 2
What is nondisjunction and when is it most likely to occur?
homologs fail to separate properly during anaphase of meiosis 1. This is more common in eggs as they age.
What is a common example of a person with aneuploid?
trisomy 21, Downs
Prader Willi is a result of what?
nondisjunction at chromosome 15- deletion of paternal ch. 15
Anglemans is a result of what?
nundisjunction where chromosome 15 of mom is lost
What is the genetic profile of someone with Edwards Syndrome?
Trisomy 18 (47XX + 18)
