Cell Cycle Flashcards
Define cell cycle
The time taken for one cell to become two cells
What are the 3 phases in the cell cycle?
Interphase, mitosis and cell division
What happens during interphase?
DNA replication, growth of organelles (cellular synthesis)
What happens during mitosis?
Nuclear division
What happens during cell division?
Splitting of the cytoplasm (cytokinesis)
What are the 4 phases in mitosis?
Prophase
Metaphase
Anaphase
Telophase
What happens during interphase?
- synthesis of proteins eg. Histones and enzymes
- DNA replication
- ATP increases
- organelles replicate
What happens during prophase?
- chromosomes shorten and thicken by condensation and become visible
- nuclear envelope break down
- centrioles move to opposite poles of the cell and form spindle fibres
What happens during metaphase?
- chromosomes line up at the equator of the cell
- attach to spindle fibre by their centromere
What happens during anaphase?
- centromere splits and chromatids pulled to opposite poles of cell
What happens during telophase?
- chromosomes uncoil and become long and thin
- nuclear envelope reforms
- cytoplasm divides (cytokinesis)
- forms 2 new genetically identical cells
What is the equation to calculate the mitotic index?
No. Of cells undergoing mitosis/ total no. Of cells x 100
What is cancer/tumour?
Uncontrolled cell division
Do viruses go through cell division?
No
How do viruses replicate?
- Attachment proteins attach to receptor of host cell
- Enveloped viruses fuse with cell membrane or move in via endocytosis and release DNA/RNA into cytoplasm or viruses inject DNA/RNA
- Infected host cell uses viral genetic information to synthesise new viral proteins/nucleic acid
- Components of new viral particle assemble
