Lecture 19 - Mutations 1 Flashcards
Differentiate between somatic mutations and germ-line mutations.
L19 S8
Somatic:
- arise in non-gamete producing tissues
- only affects the individual the mutation occurs in
Germ-line mutations:
- arise in tissues that produce gametes
- can be passed to offspring
What is a de novo mutation?
L19 S11
A new mutation that arises in a family member with no history in the rest of the family.
The mutation either occurs in the gamete or fertilized egg and can be germ-line or somatic.
Differentiate between loss of function, neutral, and silent mutations.
L19 S17
Loss of function:
-complete or partial absence of normal protein function
Neutral mutation:
-change in AA sequence but not protein function
Silent mutation:
-change in codon sequence but not AA sequence
Differentiate between missense and nonsense mutations.
L19 S18
Missense:
-alteration of a codon that changes amino acid coded for
Nonsense:
-alteration of a codon that generates a stop codon
Differentiate between forward mutations and reverse mutation.
L19 S18
Forward mutation:
-alters wild-type phenotype to mutant phenotype
Reverse mutation:
-reverts mutant phenotype to wild-type phenotype
What is the significance of trinucleotide repeats?
L19 S15
Trinucleotide repeat sequences can from hairpin loops which lead to additional trinucleotide being added to the sequence.
What is a suppressor mutation and what are the two types of suppressor mutations?
L19 S23
Suppressor mutation:
-mutation that hides the effect of another mutation
Intragenic:
-suppressor mutation is in the same gene as the mutation that it suppresses
Intergenic:
-suppressor mutation is in a different gene from mutation that is suppresses
What nucleotides can 5-bromouracil base pair with and why is this an issue?
L19 S41
5-bromouracil can base pair with both guanine and adenine.
It can replace a thymine but since it can pair with guanine, it can cause and AT to switch to a GC
