Cell Cycle Flashcards
What is the cell cycle?
- It is an continuous process were DNA is duplicated.
- Cell division occurs where daughter cells are produced.
What is the difference between unicellular and multicellular organisms?
- A uniceullar organism consists of one cell.
- A mlticeullar organism consists of more than one cell.
What is the difference between senescent and quiescent?
- Senescent means the process of growing old.
- Quiescent means cells are no longer taking part in cellular activity.
What is the purpose of checkpoints in the cell cycle?
- They enable the cell cycle to be arrested if the previous events have not been completed and they repair the damage.
What are the stages in the cell cycle?
- Interphase
- G1
- S
- G2
- M
- GO
What is the purpose of the interphase in the cell cycle?
- During this stage the cells grows and prepares itself for cell division.
- The cell spends most of its time in this stage.
- Made up of the G1,S and G2 stage.
What happens in the G1 stage?
- Classed as the growth stage and the cell increases in metabolic activity.
What happens in the S phase?
-DNA synthesis takes place.
What happens in the G2 phase?
- Takes place during the stage of protein synthesis.
- The stage to check up on the cell and to prevent it from having any damage.
What happens during the M phase?
- Nuclear division takes place during this stage.
- karyokinesis is the division of a nucleus in a cell.
What happens during the GO phase?
- The cell rests and it is not prepared for cell division.
How long is the cell cycle of a human cell?
24 hours
What are the three main stages of the cell cycle?
- Interphase
- Mitosis
- Cytokinesis
What is monitored during the checkpoints in the cell cycle?
- Cell size
- Adequate supply on nutrients.
- DNA quantity and quality.
- Favourable environment.
Describe mitosis.
- Chromosomes are duplicated in a cell, then they are segregated and separated as the cell divides and produces identical daughter cells.
- Occurs in somatic cells.
- There are five stages in mitosis and cytokinesis.
Describe prophase in mitosis.
- The genetic material condenses to prevent the chromosomes from tangling together
- The chromosomes become visible.
- Centrosomes replicate and move to opposite ends of the nucleus.
- The nucleolus disappears.
Describe the prometaphase in mitosis.
- The nuclear envelope breaks down and the centrosomes are released.
- The centrosomes interact with the chromosomes to build a miotic spindle.
- The chromosomes further condense.
What are the stages that take place during mitosis?
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis is not classed as a stage but it takes place.
What is a kinetochore?
- It is a protein.
- Attaches to the sister chromatids.
- Has an inner and outer region.
- The microtubules attach to the kinetochore.
Describe metaphase in mitosis.
- Chromosomes align on the axis (equator).
- Spindle fibres attach to the centrosomes.
- Chromosomes align randomly.
Describe anaphase in mitosis.
- The chromosomes break apart and the sister chromatids move to opposite ends of the cell.
Describe telophase in mitosis.
- The nucleolus and nuclear membrane form.
- Long
Describe cytokinesis in mitosis.
- The cytoplasm is pinched and divides into two and two identical daughter cells are produced.
Describe meiosis.
-Four haploid cells are produced and the daughter cells are not identical.
- Only occurs in gametes cells.
- Each cell contains a set of chromosomes.
- Have the number of chromosomes from a diploid daughter cell.
