Cell cycle (overviewof cell cycle) Flashcards
all living organisms are products of what?
repeated rounds of cell growth and division
cycle of duplication and division is known as the?
cell cycle
fundamental task of cell
the passing on of its genetic information to the next generation of cells
What are the 2 most basic function of the cell cycle
duplicate DNA and then segregate into two copies
What are the two major phases of the cell cycle?
(DNA synthesis) and M phase(mitosis and cytokinesis
two major events of M phase
Nuclear division, mitosis
Cytoplasmic division, or cytokinesis,
Early in mitosis at a stage called prophase
two DNA molecules are gradually disentangled and condensed into pairs of rigid, compact rods called sister chromatids, which remain linked by sister-chromatid cohesion
When the nuclear envelope disassembles later in mitosis, the sister-chromatid pairs become
attached to the?
mitotic spindle
in a stage called metaphase
Sister chromatids are attached to opposite poles of the spindle and, eventually, align at the spindle equator
start of anaphase
The destruction of sister-chromatid cohesion at the start of anaphase separates the
sister chromatids, which are pulled to opposite poles of the spindle
at telophase
The spindle is
then disassembled, and the segregated chromosomes are packaged into separate
nuclei
At Cytokinesis
cleaves the cell in two, so that each daughter
cell inherits one of the two nuclei
to allow time for growth, most cell cycles have?
gap phases
between M phase and S phase
G1 phase
between S phase and mitosis
G2 phase
four sequential phaseshase of eukaryotic cell cycle
G1 → S → G2 → M
occurs throughout the cell cycle, except during mitosis.
Cell growth
They are called interphase
G1, S, and G2
provide time for the cell to
monitor the internal and external
environment
gap phases
Why gap phases provide time for the cell to
monitor the internal and external
environment?
to ensure that conditions are
suitable and preparations are complete
before the cell commits itself to the major
upheavals of S phase and mitosis
-specialized resting state
- cell can remain for days, weeks, or even years before resuming proliferation.
G0 (G zero)
2 commitment point near the end of G1
Start (in yeasts) or the restriction point (in mammalian cells)
It is essentially the same in all eukaryotic
cells
basic organization of the cycle
What are the two mechanism that all eukaryotes appear to use similar to drive and regulate cell-cycle event
machinery and control mechanisms