Cell Cycle Flashcards
What are the main phases of cell cycle?
Interphase
Longest period of cycle
Normal cell functions (existing)
G1
S - replication of DNA
G2
Mitosis
Cell divides nuclear contents
Prophase → Metaphase → Anaphase → Telophase
Cytokinesis
Final split and formation of new, identical
cells
What is the cell cycle
The cell cycle is the series of events which cells undergo to divide and create two identical daughter cells.
What is occurring in each of the phases
Interphase
cell carries out normal functions.
G1. The cell prepares for cell division by:
- making proteins
- the cell getting bigger in mass
S - genetic material (DNA) is synthesised / replicated using
G2 - Final growth period before cell divides into two, through Mitosis.
Mitosis: contents of the nucleus are divided into two equal parts.
Cytokinesis: separation of two nuclei and cell contents
into two daughter cells.
What phases are apart of interphase
G1 phase ( gap 1)
S phase ( synthesis)
G2 phase ( gap 2)
what proportion of the cell is taken up by mitosis?
Mitosis accounts for about 10 percent of the cell cycle
what is occurring in the mitosis
Prophase–> metaphase—> Anaphase—> telaphase
What happens in Prophase
Chromosomes become visible
Nucleus membrane disappears
Centrioles begin to move to poles
metaphase
Chromosomes line up at equator
Spindle fibres are attached to centromere
Anaphase
Spindle fibres pull sister chromatids apart
Telephase
Chromosomes are separated
Nuclear membrane reforms
Cell plate or cleavage furrow forms
What are the difference between cytokinesis in animal and plant cells?
In plants:
Cell plate forms and will become the new cell wall
Plant cells cannot be “pinched” into two new daughter cells, because of the cell wall.
In animals:
Cell pinches down the middle (cleavage furrow) to split the daughter cells
How is the cell regulated to deal with problems.
The cell checks its DNA during different stages. If there’s a problem, it stops dividing, fixes the issue, or destroys itself to prevent errors.
How do mutations result in a lack of control of the cell cycle?
Eg. Disruption of normal regulation of the cell cycle can lead to diseases such as cancer. When the cell cycle proceeds without control, cells can divide without order and accumulate genetic errors that can lead to a cancerous tumor.
Mutations can disrupt genes controlling cell cycle, causing uncontrolled division, leading to cancer or cell death.