Biol 1057 - Introduction to genetic mutations

Question 1

Defiena genetic mutation

Answer 1

• Any change to the quantity or the base sequence of the DNA of an organism

Question 2

Outline mutations during the formation of gametes

Answer 2

• Germline mutation
• Heritable
• Produce distinct difference between individuals

Question 3

Outline gene mutations

Answer 3

• Change to one or more nucleotide bases in DNA
• Change in the sequence of bases in DNA
• Some are somatic mutations = occur in non-sex cells

Question 4

Brief diagram

Answer 4

Question 5

Outline the impact of point mutations on translation into amino acids

Answer 5

SUBSITUTION OF BASES
- Substitution of DNA bases that alters one amino acid of the translated protein is a mis sense mutation (Hb)
- Substitution of DNA bases that does
not alter the translated protein is a silent mutation
- Substitution of DNA bases that
alters significantly the translated protein is a non-sense mutation

Question 6

Outline an example of mis sense mutation

Answer 6

• Sickle cell disease gives mutated form of haemoglobin “HbS” Glu Replaced by Val so difficult to carry O2

Question 7

Outline the impact of 1 type of frame shift mutation on translation into amino acids

Answer 7

BASE INTERTION
- Insertion of DNA base that alters
significantly the translated protein is a mis-sense mutation
* Triplets and codons change from the point of
insertion onwards

Question 8

Outline the impact of a 2nd type of frame shift mutation on translation into amino acids

Answer 8

BASE DELETION
- Insertion of DNA base that alters
significantly the translated protein is a mis-sense mutation
- Triplets and codons change from the point of
deletion onwards

Question 9

Summarise impact of mutations on translation into amino acids

Answer 9

Mutations originating at the DNA level show their effects at the
protein level
* Alterations to DNA —- point, frame-shift mutations
* Alterations to the Protein —- mis-sense, non-sense mutations

Question 10

Outline how mutations arise

Answer 10

1. INHERITED
   * Pass down from parents to offspring
2. SPONTANEOUS
   * DNA replication errors
   * Completely random
   * Environmental factors