Cell Cycle Flashcards
What happens in metaphase?
Spindle fibres move the chromosomes so that they line up on the metaphase plate at the equator of the cell.
What happens in prophase?
The chromosomes condense and become visible as two joined chromatids. Spindle fibres attach to the chromosomes at the centromeres.
What happens in anaphase?
The spindle fibres pull the sister chromatids apart. Once they are separated, the chromatids are called chromosomes in their own right.
What happens in telophase?
The separated chromatids are pulled by spindle fibres to opposite poles to form daughter nuclei. Chromosomes start to uncoil and nuclear membrane forms.
What is cytokinesis?
Separation of the cytoplasm.
When does the G1 checkpoint occur?
Happens at the end of G1
What is monitored at the G1 checkpoint?
Cell size. There has to be sufficient cell mass to form two daughter cells. This checkpoint controls entry to the S phase.
What is checked at the G2 checkpoint?
Success of DNA replication to make sure each daughter cell can receive a complete copy of DNA.
What is Mitosis-Promoting Factor?
A protein complex that controls entry to mitosis. Mitosis will only be triggered if sufficient MPF is present.
What is monitored at the M checkpoint?
Chromosome Alignment- to ensure each daughter cell receives one chromatid from each chromosome.
Controls entry to anaphase.
What are the 3 phase in interphase?
G1
S
G2
The cell cycle consists of interphase and mitosis. Specifically when is DNA replicated?
S stage
How do you work out the mitotic index?
Number of cells undergoing mitosis/ total number of cells x 100
What is an essential gene?
Gene essential for cell survival
What is a cell specific gene?
Genes required for the function of a particular cell
