Meiosis Flashcards
What are the comparisons with Mitosis?
4 daughter cells
genetically non-identical
production of gametes
haploid
2 divisions
What is a karyotype?
visual representation of chromosomes in a cell
23 homologous pairs
What happens in prophase I?
homologous chromosomes appear
each made of two chromatids joined at the centromere
What happens in metaphase I?
spindle fibres form and homologous pairs line up at equator
independent segregation and crossing over happens
What happens in anaphase I?
no centromere split
homologous pairs pulled to opposite poles
What happens in telophase I?
nuclear membrane reforms around two haploid nuclei
What does genetic recombination increase?
genetic variation
What is the bivalent?
pair of homologous chromosomes, coiled around each other and joined at multiple points
What is the chiasmata?
points where non-sister chromatids of homologous chromosomes are joined
How is the ova specialised to their function?
jelly coat - protection
hardens after first sperm fertilises egg
How is the spermatozoa specialised to their function?
digestive enzymes in head
digest jelly coat
flagellum - swim/move
mitochondria - ATP for energy to move
