6.1.3 Somatic VS Germline Mutations

Question 1

Somatic Mutations

Answer 1

• An acquired mutation that occurs in somatic cells
• Occurs spontaneously in the S phase of the cell cycle when the DNA is vulnerable because of replication. If not repaired in the G2 phase, the mutation is passed on to daughter cells and spreads.
• The error will continue to amplify within that tissue, which may result in a phenotypic difference, such as pigmented cells (carcinoma), a tumour (cancer) or other disease.
• Results in a genetically mosaic individual

Question 2

Germline Mutations

Answer 2

• A hereditary mutation that occurs in the sexual reproductive cells that become gametes
• Occurs during gametogenesis (meiosis)
• When an embryo forms from the mutated gamete, the mutation is replicated in every cell of the resulting offspring.