Genetic mutations

Question 1

Define mutation.

Answer 1

a change in the nucleotide sequence of DNA that can be passed on from one cell, or organism, to another

Question 2

State 2 main causes of mutation.

Answer 2

1. Error in DNA replication
2. External influences eg. chemicals or radiation

Question 3

What are germ line mutations?

Answer 3

• In germ line cells
• mutation passed on to offsprings (and subsequently their offsprings)

Question 4

What are somatic mutations?

Answer 4

• In somatic cells
• Passed on to daughter cells during mitosis
• not passed on to sexually produced offspring

Question 5

Why are most mutations not harmful?

Answer 5

• It’s in non-coding areas
• Synonymous mutation: It does not change the amino accid

Question 6

What are the possible effects of mutations?

Answer 6

1. No effect
2. loss in function
3. increased/enhanced/altered function

Question 7

What is a point mutation?

Answer 7

Mutation that only affects one nucleotide.

Question 8

What are the types of point mutations?

Answer 8

1. Single nucleotide polymorphism (SNP)
2. Indels (insertion or deletion)

Question 9

Why are indel mutations espescially problematic?

Answer 9

Because they cause frameshift that cuases all bases after the point mutation to shift, which results in a mutation at every codon after mutation point arise. The amino acid sequence of the protein will be totally changed, resulting in huge impact on function.