Mitosis and replication Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What must happen before a cell can divide?

A
  • organelles must replicate
  • DNA must replicate
  • cell must grow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is it important that mitosis produces genetically identical copies of a parent cell?

A
  • growth of new cells
  • repair of damaged tissues
  • asexual reproduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the stages of the cell cycle?

A

Interphase: - G1 (cell growth, organelle synthesis and replication)
- Synthesis - DNA replication
- G2 - (growth and protein synthesis for replication)

Prophase

Metaphase

Anaphase

Telophase

Cell division (cytokinesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens during prophase?

A
  • nuclear membrane and nucleolus disappears
  • chromosomes condense and stain darker
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens during metaphase?

A
  • centrioles begin to produce spindlefibres
  • chromosomes arrange in the middle of the cell on the equator, held by centromeres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens during anaphase?

A
  • spindlefibres attached to centromeres begin to contract and shorten
  • ## as the spindlefibres shorten, the chromatids are separated and pulled to opposite sides of the cell (different poles)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens during telophase?

A
  • spindlefibres disintegrate
  • chromosomes disperse and become long and thin and the nuclear membrane reforms
  • cell plate forms and membrane begins to cleave
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the formula for mitotic index?

A

number of cells with visible chromosomes divided by total number of cells observed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does a tumour develop?

A
  • initially an early tumour is formed through uncontrolled cell division
  • the tumour enlarges from the edges (has no capsule so can uncontrollably grow) and begins to develop blood vessels and lymphatic vessels
  • ?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do mutations affect the process of tumour growth?

A
  • 2 genes called protoncogenes and tumour supressor genes
  • if they are mutated the cell cycle cannot be controlled and this will lead to abnormal growth which causes tumours
  • if both genes are mutated then the cancer will be more aggressive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how do prokaryotic cells replicate?

A
  • replication of plasmids, circular DNA and ribosomes
  • cell is ready to divide so replicated molecules attach to the membrane
  • membrane grows which pulls molecules apart
  • start of cell division - cell begins to cleave
  • the cell splits into 2 separate daughter cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how do viruses replicate?

A
  • the virus attaches to a target cell eg. epithilial cells
  • the cell engulfs the virus by endocytosis
  • viral contents are released, viral RNA enters the nucleus where it is replicated by the viral RNA polymerase
  • viral mRNA is used to make viral proteins
  • new viral particles are made and released into the extracellular fluid. The cell, which is not killed in the process, continues to make new viruses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly