1. (1) Division and differentiation in human cells
(F) Cancer Cells
(A) Somatic cells
Human Cells
(E) Uses of stem cells
(B) Differentiation in cells
(D) Germline cells
(C) Stem cells

2. Division and differentiation in human cells (D)
State what is meant by germline cells
Define the processes of mitosis and meiosis in a germline cell
Compare the process of mitosis and meiosis
Describe the effect of a mutation present in a germline cell
Describe how the chromosome complement is maintained during cell division

3. Key Words Diploid Gamete Haploid Mitosis Meiosis
Homologous
Meiosis
The term given to a ‘sex cell’
(Such as sperm or eggs)
The term given to a cell containing 2 sets of chromosomes
(Human somatic cells contain 46 chromosomes – 2 sets of 23 chromosomes)
The term given to a cell containing 1 set of chromosomes
(half the genetic information of the parent cell)
(gametes contain 23 chromosomes – 1 set)
Term used to describe 2 chromosomes which have the same genes
(Diploid cells have 23 pairs of homologous chromosomes)
Form of cell division, where by 2 identical diploid cells are produced
Form of cell division where by 4 genetically different haploid gamete cells are produced

4. Germline cells
Whilst somatic cells eventually form to create the different body tissues, germline cells eventually give rise to gametes (sex cells: eggs and sperm).

5. Matching set of chromosomes
Every organisms has 2 matching sets of chromosomes. In humans, the 46 chromosomes can be arranged as 23 pairs.
Each pair is known as a homologous pair (homologous = same)

6. What are the differences between the newly formed cells in mitosis and those formed in meiosis?

7. Division of germline cells
Germline cells can divide by mitosis to produce more germline cells (the chromosome complement is maintained).
They can also divide by meiosis to produce haploid gametes.
meiosis video

8. All sex cells are haploid cells and contain only 1 set of chromosomes (23).
After fertilisation, the complete 23 pairs of homologous chromosomes is restored in the new zygote that is formed (a diploid cell).
♀ Parent 46 chromosomes
♂ Parent 46 chromosomes
Diploid (2n)
Meiosis
Egg 23 Chromosomes
Sperm 23 Chromosomes
Haploid (n)
Fertilisation
Zygote 46 chromosomes
Diploid (2n)

9. What is a mutation?
It is a change to the original genetic material (DNA, genes or chromosomes)

10. If a mutation occurs during meiosis it will be passed on to the offspring
Normal division
Mutation

11. If a mutation occurs during meiosis it will be passed on to the offspring
Cells with a mutation
Normal cells

12. TASK: Use your notes to complete the following table
Mitosis VS. Meiosis
Characteristic
Mitosis
Meiosis
Purpose of division
Number of cells produced
Description of cells
Number of chromosomes in each cell
Types of cells that undergo this division
Effect of mutations