meiosis Flashcards
reproductive cells are also known as
gametes or sex cells
what are the two types of reproductive cells?
sperm cells and egg cells
how are reproductive cells formed
through a cell diving process called meiosis
what are the stages of meiosis II and I
prophase II and I
metaphase II and I
anaphase II and I
telophase II and I
what happens during Prophase II
sister chromatids are not genetically identical due to cross over from meiosis I, 1 copy of each chromosome are in the cell and no longer diploid, nuclear membrane starts of disappear
what happens during prophase I
nuclear membranes disappear,genetic material from female egg exchanges with male sperm thinf produces genetic variation called crossing over, and homologous chromosomes can come together crossing over pairing them and spindle forms
metaphase I and II
chromosomes line up in the middle of metaphase 1 of chromosomes are in pairs but metaphase 2 they aren’t
what is independent assortment
when homologous chromosomes separate there are two possibilities
what happens during anaphase I and II
they both pull the chromosomes to each sides of the cell but for anaphase I independently assortment occurs
what happens during telophase I and II
nuclear membrane returns, cytokinesis is ready but during telophase II there is 4 nuclei instead of 2 like in telophase I
what is crossing over?
when genetic material from female eggs can exchange with male sperm, this produces genetic variation
what is the haploid number? 
1n or n
what is the diploid number?
2n
what are homologous chromosomes?
paired chromosomes which only occur in diploid
how many cell divisions does meiosis contain and what are they?
it goes under meiosis I and meiosis II
during Meiosis I what happens?
one diploid cell divides into two haploid cells
what happens in meiosis II?
the two haploid cells divide into 4 haploid sex cells (gametes produced are not identical to the original diploid cell)
what is interkensis
Interkinesis is a stage that occurs between meiosis, one and meiosis two during the stage, the cell grows and creates proteins ( DNA DOES NOT REPLICATE)
what happens during cytokinesis after telophase II
The cell divides into two for total of four haploid cells the four cells represents for gamete’s. Each gamete is a haploid cell with only one of the sister chromatids. The gametes are now ready for fertilization through sexual reproduction.
