3.7 Mitosis

Question 1

Describe the first step of mitosis

Answer 1

Prophase
1. Chromatin condenses into chromosomes (now visible) - 2 sister chromatids and centromere
2. Nucleolus disappears
3. Nuclear membrane disappears
4. Centrioles move towards poles
5. Centrioles produce spindle fibres

Question 2

Describe the second step of mitosis

Answer 2

Metaphase
1. Spindle fibres attach to the centromere of the chromosome
2. This form an equatorial plate

Question 3

Describe the third step of mitosis

Answer 3

Anaphase
1. Chromosomes split at the centromere due to the spindle fibres
2. The chromosomes are pulled to opposite poles (v-shaped)

Question 4

Describe the fourth step of mitosis

Answer 4

Telophase
1. Spindle fibres disappear
2. Chromosomes detach from spindle fibres
3. Chromosomes uncoil to form chromatin
4. Nucleolus reforms
5. Nuclear envelope reforms