Introduction to cell cycle and mitosis (self directed)

Question 1

order of cell cycle stages

Answer 1

Mitosis
(g0)
G1
S
G2
Mitosis

Question 2

What are G0?

Answer 2

Non-cyclers

Question 3

What is G1

Answer 3

Control point to check whether cells can enter the S phase

Question 4

What’s S phase

Answer 4

replication of:

• DNA
• RNA
• proteins

Question 5

whats G2

Answer 5

final prep of mitosis

Question 6

What happens in prophase

Answer 6

• Chromatin condenses to form visible chromosomes
• Centrioles replicate
• Centrioles move apart to form 2 poles and act as ‘Microtubule-organising centers (MTOC’s)
• Microtubules form mitotic spindle apparatus between centrioles

Question 7

What happens in prometaphase

Answer 7

• Nuclei regress
• Nuclear membrane disassembles
• Chromosomes move towards equator and interact with microtubules
• Pair of sister chromatids has attachment site which is called kinetochore and attaches to spindle

Question 8

What is a kinetochore

Answer 8

Attachment site on sister chromatids which attach to spindles

Question 9

What happens in metaphase

Answer 9

• Centre of cell forms metaphase plate
• Chromosomes go to middle
• Microtubules run from pole to pole or pole to chromosome
• THe latter microtubules run to the centimes of sister chromatids and attach at the kinetochores

Question 10

What happens in anaphase

Answer 10

Chromosomes pulled along by microtubules

Question 11

What happens in telophase

Answer 11

• Chromosomes reach poles and become less condensed
• Nuclear membrane reassembles
• Cleavage furrow begins around equator
• Spindle disappears
• Nucleoli reappear