meiosis (f) Flashcards
what is meiosis
makes sperm and egg cells
reduction division
how many chromosomes are in sperm and egg cells
23 chromosomes
what is reduction division
starter cells should be primary sperm to cycle (in male) or primary oocyte (in females)
how many divisions is in meiosis
2
interphase
growth
dna replication
cell functions
how many chromatids are in 46 chromosomes
96 chromatids
prophase 1
chromosomes condense and thicken
line up with homologous pairs
homologous chromosomes
same size (approximately) and match up, happens during prophase 1
crossing over
transferring genetic information
metaphase 1
chromosomes are going to the middle of the cell
still in pairs
not single line
anaphase 1
chromosomes are going to be pulled away by spindle fibers
telophase 1
two newly formed nucleus
two new cells
cytokinesis starts
prophase 2
no homologous pairs
chromosomes and spindle fibers form
metaphase 2
chromosomes line up in the middle (single file line)
anaphase 2
chromatids get pulled away by spindle fibers
telophase 2
nuclei reform
2 cells are going to divide (4 cells are formed, not identical)
cyctokenesis splits cytoplasm
what is the end result of meiosis?
4 male sperm cells
are the 4 sperm cells from the end result of meiosis identical?
they are not identical and different from original and other cells
what are two differences between meiosis 1 and meiosis 2
meiosis 1 -> homologous chromosomes separate
meiosis 2 -> sister chromatids separate
meiosis 2 -> produces 4 haploid daughter cells
meiosis 1 -> produces 2 diploid daughter cells
what is nondisjuntion
the failure of one or more pairs of homologous chromosomes or sister chromatids to separate during division
somatic cells
any cell of a living organism other than the reproductive cells.
sex cells
organism’s reproductive cells
sister chromatids
condensed dna that are identical, made of chromatin
chromosomes
two chromatids put together by a centromere
fertilization
combining gametes
zygote
a single cell that contains genes from parents
gamete
sperm and egg cells
diploid
same number of chormosmes as parent cell
what’s the difference between a sex cell and a body cell
sex cell -> reproduction
body cells -> every day tasks
sex cells -> one set of chromosomes
body cells -> two sets of chromosomes
