Cell cycle

Question 1

What is the cell cycle (simple) ?

Answer 1

-It starts with a parent cell and ends with 2 genetically identical daughter cells

Question 2

What are the uses of cell cycle?

Answer 2

-Growth,repair and replacement of cells in tissues of multicellular organisms.
- Also essential for asexual reproduction in plants,fungi, some animals and single celled organisms.

Question 3

What stage does a cell spend most of its time in?

Answer 3

• interphase

Question 4

In what stage does the DNA replicate?

Answer 4

• s phase

Question 5

How can you tell that a chromosome has been replicated ?

Answer 5

• Looks like and X / has a copy of itself attached

Question 6

In what stage does the nucleus divide?

Answer 6

• Mitosis

Question 7

In what stage does the cell divide?

Answer 7

• cytokinesis

Question 8

What stage are specialised (differentiated cells) in?

Answer 8

• G0 - cells have left the cell cycle

Question 9

Draw and explain the cell cycle on your whiteboard

Answer 9

check on google did you get it right ?

Question 10

What metabolic functions occur during interphase ?

Answer 10

In addition to normal metabolic functions:
- DNA replication
- Checking that replication is accurate
- Production of new organelles
- Cells increase in size
-** Protein synthesis**
- ATP production increases
-

Question 11

What happens in G1 first growth phase?

Answer 11

• Transcription / translation / Protein synthesis occurs​
• Organelles duplicate​
• Cell grows in size.
• G1 checkpoint: ​
• The cell checks that the chemicals needed for replication are present and it checks for any damage to the DNA before entering S phase

Question 12

What is G0 phase ?

Answer 12

A resting phase can be triggered in early G1​
- Cells which enter this phase do not go on to replicate.​
- Cells in G0 may:​
- Differentiate and become specialised​
- Undergo programmed cell death (apoptosis)​
- Become senescent (have completed the maximum number of cell divisions)

Question 13

What takes place in the S phase ?

Answer 13

**S: Synthesis phase: **
-DNA is replicated
-During DNA replication DNA polymerase makes many random and spontaneous errors resulting in mutations to DNA ​
-These can be beneficial, neutral or harmful

Question 14

What takes place in G2 ?

Answer 14

-Cell grows in size​
-ATP production increases​
-Protein synthesis for spindle fibres for mitosis.
G2 checkpoint: ​
-The cell checks whether all the DNA has been replicated without any damage. If it has the cell can enter mitosis

Question 15

PMAT - pretty mary aint tall

What are the stages of mitosis and what is it?

Answer 15

• Prophase
• Metaphase
• Anaphase
• Telophase
• mitosis is a form of cell division that produces identical cells, there are four
  stages of mitosis: prophase, metaphase, anaphase and telophase.

Question 16

What happens in prophase ?

Answer 16

• Chromosomes condense and become visible
• Nuclear envelope breaks down
• Nucleolus breaks up and disappears
  -Centrioles migrate to opposite poles
• Mitotic spindle starts to form.

Question 17

What happens in the metaphase

Answer 17

• Chromosomes (each with two chromotids) are organised into a plane across the centre of the cell.
• Spindles fibres attach onto the centrometres.
• Metaphase checkpoint - the cell checks all the chromosomes are attached to spindle fibres.

Question 18

What happens in the anaphase ?

Answer 18

• spindle fibres contract and the centrometres divide
• This pulls the sister chromotids to opposite poles
• Cells starts to elongate

Question 19

What happens in the telophase ?

Answer 19

• chromosomes no longer visible
• nuclear envelope and nucleolous reforms
• spindle disintergrates

Question 20

What is cytokinesis ?

Answer 20

• during cytokinesis the parent and replicated organelles move toopposite sides of the cell and the cytoplasm divides thus producing two daughter
  cells

Question 21

What are the types of cytokinesis ?

Answer 21

• Animal cell
• Plant cell

Question 22

What happens in animal cell cytokinesis ?

Answer 22

• The contractile ring (containing microfilaments made up of actin) forms inbetween 2 daughter cells - needs ATP
• Cell surface membrane + cytoplasm divide
• Really quick process

Question 23

What happens in a plant cell during cytokinesis ?

Answer 23

• A new cell wall forms inbetween two daughter cells
• Vesicles containing cell wall components start to arrange themselves at the centre of the cell
• Eventually vesicles fuse forming the new cell wall