chapter 4 Flashcards
(24 cards)
Stomatic cells are
aka body cells
and diploid
occur in mitosis only
gametes are
sex cells, occur only in meiosis
haploid
humans have _ chromosomes in meiosis and _ in mitosis
23, 46
what are zygotes
diploid- restores number to 46. formed when sperm meets eggs
what is fertilization
the union of haploid gametes to produce diploid zygotes
when do homolhous pairs cross over in meiosis
in prophase 1
what happens in recombination
maternal and paternal homologs recombine to create new combos of alleles
what are the 3 stages of prophase
leptozene, zygotene, pachtyene
leptotene
chromosomes thicken and move to poles
zygotene
sypnatomeal complx forms to hold homo pairs together
pachytene
crossing over occurs
diplotene
tetrad forms and sp dissolves
diakensis
chromatids thicken
when do sister chromatids seperate
in meiosis II. equational divsion
mitosis produces_ and meiosis _ number of daughter cells
2 indetical daughter cells
4 unique daughter cells
haploid and diploid cells only occur in _ and diploid in _
Mitosis and meiosis
what is oogenesis
formation of one ovum per one oocyte
which form is assymetical meiosius and which is syymetircal
oogenesis and spermogensis
how many polar bodys form and does it occur in speromgenesis
2-3 polar bodies
what are polar bodies
a small nonfunctional cell produced during oogensis
what is spermatogenesis
4 haploid sperm produced from one spermatocyte
when does oogensis start
meiosis 1 starts before birth and halts in prophase 1 and resumes in ourberty
when is meiosis 1 complete in females
when it produces one oocte turns into secondary oocyte.
when does meiosius 11 start and end in females
when fertilization occurs. ends when one ovum is produced
