B3 Cell Division and Sex Determination

Question 1

Cells splitting into 2 new daughter cells is called

Answer 1

cytokinesis

Question 2

The two daughter cells produced by mitosis:

Answer 2

are genetically identical to each other
are genetically identical to the parent cell which produced them
have the same number of chromosomes as the parent cell.

Question 3

Mitosis and Cancer

Answer 3

As a cell prepares for mitosis during interphase, the cell cycle pauses temporarily for a short time to check the cell is healthy and the DNA has been copied correctly.
If errors are detected in a cell, such as a mutation in the DNA that cannot be repaired, the cell will be destroyed.
If a cell with changes is not destroyed, the cell cycle will continue and the cell will divide by mitosis.
- uncontrolled growth and division

Question 4

During interphase, the cell prepares for mitosis by

Answer 4

chromosomes in the nucleus are replicating and

the cell respires to provide energy for mitosis.

Question 5

Role of mitosis

Answer 5

increasing cell numbers, repair of tissues, replacement of worn out cells and asexual reproduction.

Question 6

Meiosis

Answer 6

• Chromosome number halved from diploid to haploid
• production of gametes
• each daughter cell genetically different
• Full chromosome complement is restored at fertilisation

Question 7

asexual reproduction

Answer 7

involves one parent and that offspring are genetically identical when no mutations occur

Question 8

Sexual reproduction

Answer 8

involves two parents and that offspring are genetically different in relation to each other and the parents, leading to (increased) variation.