meiosis Flashcards
what is the point where chromatids cross to swap DNA called
chiasmata
what is independent segregation
random change of which pairs of chromatids go where using spindle fibres from homologous chromosomes
what do the 2 divisions in meiosis form
the formation of four haploid daughter cells from a single diploid parent cell
how do genetically different cells form in meiosis
from the independent segregation of homologous chromosomes
how does genetic variation occur
crossing over between between homologous chromosomes resulting in further genetic variation among daughter cells
anaphase 1 also has random chromosomes at each pole further varying genetic info
describe what happens in prophase 1
chromosomes condense
homologous chromosomes pair up
describe a tetrad
paired up homologous chromosomes
describe metaphase 1
homologous strands line up together in centre of cell
describe how dna is exchanged
while lined up, chromosomes cross over and swap genetic info at the chiasmata
what are chromosomes with swapped genetic information called
recombinant chromosomes
describe anaphase 1
random chromosomes are pulled to opposite poles by contracting spindle fibres
give the name of homologous chromosomes going to opposite poles randomly
independent segregation
describe prophase 2
chromosomes condense again, each cell from mitosis 1 prepares for division
describe telophase 1
nuclear membrane forms around each pole to form 2 daughter cells
( division 1)
describe telophase 2
chromosomes line up at equator of 2 cells
describe anaphase 2
sister chromatids are pulled to opposite poles
describe telophase 2
another cell division occurs, splitting chromosomes into their own cells
