Cell Cycles

Question 1

When does mitosis occur in the cell cycle? What occurs in the stage before it?

Answer 1

After interphase where DNA replication occurs

Question 2

Order the stages of mitosis

Answer 2

Prophase
Metaphase
Anaphase
Telophase

Question 3

Describe prophase

Answer 3

Chromosomes become visible
Centrioles move to poles
Spindle fibres develop between the poles
Nuclear envelope breaks down

Question 4

Describe Metaphase

Answer 4

Chromosomes line up at the equator of the cell

Question 5

Describe anaphase

Answer 5

Centromeres divide into two

Spindle fibres pull centromeres to the poles

Question 6

Describe telophase

Answer 6

Chromosomes reached poles become larger and thinner
Nuclear envelope reforms
Cytokinesis occurs = two seperate cells

Question 7

Describe how division occurs in prokaryotes, why isnt there always a 50:50 genetic split

Answer 7

Binary fisson
Circular DNA molecule replicates
Copies attach to cell surface membrane
Plasmids replicate
Membrane grows between DNA molecules and pinches inwards separating the two cells
Not 50:50 because plasmid movement is random

Question 8

Give three steps of the cell cycle

Answer 8

Interphase
Mitosis
Cytokineis