Cell cycle and cell division Flashcards
what is the duration of a cell cycle of yeast ?
90 min
what is the duration of a cell cycle of a fibroblast cell ?
24 hrs
cell cycle is under genetic control of which enzymes ?
- cyclin
- CDK - cyclin dependent protein kinase / cell division kinase
in which stage the DNA replication takes place ?
S phase
what is the duration of cell cycle of Ecoli ?
20 min
what are the two phases of the cell cycle ?
- interphase
- m phase
interphase is also known as ?
prepratory/non dividing/resting phase
x% of time is required for interphase ?
95% = 23hrs
x% of time is required for m phase ?
5% = 1hr
interphase is divided into which three stages ?
- G1 phase
- S phase
- G2 phase
m phase is divided in which two stages ?
- karyokinesis
- cytokinesis
duration of G1 phase
11hrs
duration of s phase
8hrs
duration of G2 phase
4 hrs
karyokinesis of m phase is divided into which 4 stages ?
- prophase
- metaphase
- anaphase
- telophase
time interval between previous mitosis and initiation of DNA replication is called ?
G1 phase
in G1 phase cell is in which metabolic state ?
highly metabolically actives state.
synthesis of what takes place in G1 phase ?
RNA, Protein, ATP synthesis takes place
maximum growth in which cell organelles takes place in G1 phase ?
nucleus and cytoplasm
which cell organelles do not replicate in G1 phase ?
mitochondria and chloraplast
a point at the end of the G1 phase when crossed the cell is not able to enter into G1 phase again is called________ in mammals and _________ in yeast ?
restriction point in mammals
start point in yeast
DNA synthesis takes place in which phase ?
S phase
in animal cell which cell organelle duplicates in S phase ?
centriole
which protein gets synthesized in the S phase ?
Histone protein
amount of content of DNA gets _______ in S phase
double
amount of chromosome _________ in s phase
remains same
shortest phase of interphase is
G2 phase
G2 phase is also called
cytoplasmic growth phase
what get synthesized in G2 phase ?
RNA, protein, ATP synthesis
duplication of which cell organelle takes place in G2 phase ?
mitochondria and chloroplast
which monomer protein forms in G2 phase ?
α , β - tubulin monomer protein
G0 phase is also known as
quiescent stage
G0 stage metabolically ________ but __________ for cell division
metabolically active but inactive for cell division
which cells do not show division ?
heart cells and most of the nerve cells
what is apoptosis ?
natural cell death program
unavaibility of _________ leads to G0 stage
mitogens
what is mitotic poison ?
they oppose mitosis
mitogens in plants are
auxin and cytokinin
actual cell division phase is
M phase
in animal cells mitosis usually takes place in which type of cell ?
diploid somatic cells ( non reproductive cells )
examples of haploid cells are
male drone species honey bees
in which haploid cell does mitosis takes place ?
marchantina
mitosis is also known as
equational division
which is the most dramatic phase of cell cycle ?
M phase
which is the first stage of karyokinesis of mitosis
prophase
which is the longest phase of karyokinesis ?
prophase
DNA molecules are not distinct but intertwined in which phase
G2 phase
prophase is marked by
initiation of condensation of chromosomal material
centriole begins to move towards the opposite poles in which phase ?
prophase
prophase is divide in two phases
early prophase and late prophase
chromosomes appear as long, thin, single stranded structure in which phase
early prophase
in early prophase nucleolus is attached to chromosome at ______________
nuclear organiser region
in early prophase chromatin undergo dehydration to form long, thin and coiled structure this process is called as
spiralization
in early prophase chromosome ends are indistinct and appear ball of wool called as
sprime stage
multi-protein complex innvolved condensation of chromosome in late prophase are
condensin
cohesin
kinetochore protein gets mature in ___________prophase
late prophase
centriole reach to the opposite poles and start spindle formation in ___________prophase and start radiating out __________
late prophase
microtubules
nuclear envelope, nucleolus, golgi complex, endoplasmic reticulum ___________ in late prophase
disappear
the two aster rays together with spindle fibers forms
mitotic apparatus
prometaphase is charctersised by ______________
complete disintegration of nuclear envelope and nucleolus
aster formation is completed and mitotic spindle is attached to kinetochore in which transition phase ?
transition to metaphase / prometaphase
the start of metaphase is marked by
complete disintegration of the nuclear envelope
best stage to study the morphology of the chromosome is
metaphase
kinetochore acts as a __________ for the spindle fibers
attachment site
what is metakinesis ?
the tightening of chromosomal fibers brings all the chromosomes at he equator of the cell in metaphase
it is also known as compression
metaphase is characterised by
allignement of all the chromosomes at the equator of the cell