Cell Cycle Flashcards
Stages of the cell cycle
Interphase, prophase, metaphase,anaphase, telophase
What happens in prophase
- chromosomes become visible
- spindle fibres develop from centrioles
- nucleolus disappears
- nuclear envelope breaks down
- chromosomes free in cytoplasm
What happens in metaphase
- chromosomes align in the centre of the cell
- spindle fibres from the poles attach to the centromeres
What happens in anaphase
- centromeres divide in two, individual chromatids pulled apart
- chromatids pulled to opposite sides of the cell
What happens in telophase
- chromosomes reach poles, becoming longer and thinner before disappearing and leaving chromatin
- nuclear envelope reforms
- nucleolus reforms
- spindle disintegrates
What is cytokinesis
The division of the cytoplasm
What is the importance of mitosis
-growth
-repair of damaged tissue
-reproduction (single celled organisms)
Equation for mitosis index
(Number of cells with condensed chromosomes( pmat) / total number of cells) x100
What are the stages of interphase
Gap stage 1
S phase
Gap stage 2
What happens in G1
Cell grows to double the size
What happens in s phase
DNA synthesis occurs in cell (dna replication)
What happens in g2
Organelles replicated
Biosynthesis occurs-production of organic products like amino acids
Describe binary fission in bacteria
- replication of circular dna
- replication of plasmids
- division of cytoplasm to produce daughter cells
