cell division Flashcards
division of prokaryotes
binary fission
type of cell produced in meiosis
haploid
chromosome number of mosquito
6
chromosome number of adders tongue fern
1262
chromosome number of humans (diploid)
46
chromosome number of chimp
48
chromosome number of potato
48
chromosome number of dog
78
chromosome number of onion
16
what happends during g1
cells are recovering from earlier cell division
synthesize component for cell growth
dna synthesis
what happens during s phase
dna replication, synthesis
dna is undergoing __ model of replication
semi-conservative
what happens during g2 phase
more growth
checking replication of dna
chromosomes condense - tightly coiled
composition of chromosomes
DNA, RNA, proteins (histones)
unit of dna wrapped around histone
nucleosome
sister chromatids are attached by proteins called
cohesins
what happens during prophase
chromosomes shorten
centrioles move to opposite side
nuclear envelope disappears
spindle apparatus begins to form
what happens during metaphase
chromosomes line up at along center of cell
chromosomes attach to spindle fibers
spindle fibers are clearly visible
in animal cells, spindle fibers originate from __
centrioles
in plant cells, __ forms like a scaffold for cell plate assembly
phragmoplast
when does spindle fiber begin to break
anaphase
what happens in telophase
dna uncoils
spindle and astral fibers completely disappear
cytokinesis happens with most cells
cytoplasm and organelles move
difference between cell movement of plant and animal cell during telophase
animal cell - inward or invaginates and forms cleavage furrow
plant cell - from the middle outward
cells that do not undergo cytokinesis
coenobium or coenocytes
what happens when a cell does not undergo cytokinesis
presence of multiple nuclei
pairing of homologous chromosomes
synapsis
exchange of segments of homologous chromosomes
crossing over
when does synapsis and crossing over occur
prophase I
point of crossing over
chiasmata
does dna double before meiosis II
no
most important checkpoint
g1
if the cell does not pass through g1 phase, what will happen
it will proceed to the g0 phase
what is checked in m checkpoint
chromosome attachment after prometaphase to proceed with anaphase
when is m checkpoint happening
prometaphase
types of regulatory proteins involved in cell cycle control
cyclin and cyclin-dependent kinases
cyclin-cdk complex that triggers a cell’s passage past the g2 phase checkpoint into the m phase
maturation-promoting factor (MPF)
when does mpf and cdk peak
mitosis
signal for anaphase to proceed is transmitted through
anaphase-promoting complex or APC
function of APC
activates proteins that remove the cohesin
