Cell division (mitosis)

Question 1

What is mitosis?

Answer 1

Replication of eukaryotic cells to produce 2 genetically identical daughter cells

Question 2

Why is mitosis needed?

Answer 2

For the growth of multicellular organisms
To repair any damaged tissue

Question 3

What does the cell cycle consist of?

Answer 3

Cell growth and replication

Question 4

Explain what happens during interphase

Answer 4

Cell grows and new proteins are made
DNA unravels and replicates
Organelles are replicated and ATP content is increased

Question 5

Name the 4 stages of mitosis

Answer 5

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Question 6

Describe what happens during prophase

Answer 6

Chromosomes condense
Centrioles start moving to opposite ends of the cell forming a spindle
Nuclear envelope breaks down and chromosomes lie free in the cytoplasm

Question 7

Describe what happens during metaphase

Answer 7

Chromosomes line up in the middle of cell and become attached to spindle by centromere

Question 8

Describe what happens during anaphase

Answer 8

Centromeres divide separating sister chromatids
Spindles contract pulling chromatids to opposite poles of spindle
Chromatids appear ‘V’ shaped

Question 9

Describe what happens during telophase

Answer 9

Chromatids uncoil and become thin (chromosomes)
Nuclear envelope forms around each group of chromosomes = 2 nuclei
Division of cytoplasm finishes

Question 10

What is the equation for mitotic index?

Answer 10

number of cells in the field of view undergoing cell division / total number of cells in field of view

Question 11

What is cancer?

Answer 11

A tumour that invades surrounding tissues

Question 12

How is a tumour formed?

Answer 12

From a mutation in a gene that controls cell division. This leads to uncontrolled cell growth and the formation of a tumour

Question 13

Describe cancer treatments

Answer 13

Chemotherapy prevents the synthesis of enzymes needed for DNA replication
Radiation damages DNA so it can’t replicate