Mitosis Flashcards
interphase
interphase
(2 cells in interphase)
early prophase
middle prophase
late prophase
late prophase
metaphase
metaphase
beginning of anaphase
late anaphase
late anaphase
telophase
late telophase
late telophase
completed telophase
name the three phases of interphase
G1, S phase, and G2
what happens in G1 phase
cell grows in size
what happens in S phase
chromosomes duplicate (still a diploid cell)
what happens in G2 phase
centrioles duplicate
- now have 2 pairs, 4 total
which is the longest phase(s) of mitosis
prophase and telophase
20-30 mins
what are the 4 steps of prophase
- nuclear membrane disappears
- chromosomes condense / get shorter and fatter
- spindle fibers grow and form mitotic apparatus
- chromosomes attach to spindle fibers randomly
what are the steps of metaphase
chromosomes line up in middle of mitotic apparatus
- spindle fibers are attached to the kinetochore region of the chromosome centromere (this happened in prophase)
what are the 3 steps of anaphase
- kinetochore spindle fibers shorten (pulling in separate ways and split each chromosome in 1/2)
- chromatids separate and become daughter chromosomes
- polar spindle fibers continue to lengthen
what are the 4 steps of telophase
- spindle fibers disappear
- chromosomes disperse (start to unfold)
- nuclear membrane reappears
- cytokinesis (happens while step 1-3 are occurring– envagination of plasma membrane)
- at end you have 2 daughter cells
what type of cell do you start with and end with for mitosis
1 diploid cell and end with 2 daughter diploid cells
what is G0 phase
- intermediate phase between G1 and S phase
- resting phase; no reproduction
- some cells stay here like cardiac and nerve
whats a homologous cell
each chromosome has same genes on same locus (doesnt mean they have the same alleles– copy of genes)
what does homozygous mean
2 of the same alleles are on 2 homologs
what does heterozygous mean
2 different alleles on 2 homologs
what is a chromatid and how many do you have after S phase
- it’s each copy of a chromosome
- 2 chromatids on each chromosome
whats the breakdown of 23 chromosome pairs
22 pairs are autologs
1 pair are sex chromosomes
chromosome pairings for male vs. female
male– XY
female– XX
Y is only real “sex” determining chromosome
what is the reduction division step of meiosis and what does that mean
- after meiosis 1 we have 2 haploid cells
- means we have gone from diploid to haploid
how many haploid cells do you have after meiosis 2
4
