Unit 1 - Topic 5 - Protein control of cell division - Section B - The cell cycle Flashcards
The cell cycle consists of what to phases
Interphase and Mitotic (M) phase
Describe interphase
Interphase involves growth and DNA synthesis including G1, a growth phase; S phase, during which the DNA is replicated; and G2, a further growth phase.
The mitotic phase involves what two things
Mitosis and cytokinesis
Describe mitosis and cytokinesis
In mitosis the chromosomal material is separated by the spindle microtubules. This is followed by cytokinesis, in which the cytoplasm is separated into two daughter cells
What are the 4 phases of mitosis
Prophase, Metaphase, anaphase and telophase
Describe prophase
DNA condenses into chromosomes each consisting of two sister chromatids. Nuclear membrane breaks down; spindle microtubules extend from the MTOC by polymerisation and attach to chromosomes via their kinetochores in the centromere region.
Describe metaphase
Chromosomes are aligned at the metaphase plate (equator of the spindle)
Describe anaphase
As spindle microtubules shorten by depolymerisation, sister chromatids are separated, and the chromosomes are pulled to opposite poles
Describe telophase
The chromosomes decondense and nuclear membranes are formed around them.