Mutations

Question 1

What is a mutation?

Answer 1

• random change in base sequence of DNA

Question 2

What are examples of mutagenic agents?

Answer 2

• high energy radiation
• x rays
• carcinogen

Question 3

How does a deletion mutation alter the structure of a gene?

Answer 3

• removal of one or more bases
•causes frameshift

Question 4

How does deletion have a greater affect than substitution?

Answer 4

• deletion causes frameshift
• changes aa sequence
• substitution only alters one codon

Question 5

How can a mutation cause an aa to be missing?

Answer 5

• loss of 3 bases

Question 6

What happens when a mutation occurs on the intron?

Answer 6

• doesn’t effect mRNA
• only exons coded

Question 7

How can a mutation lead to the production of a non-functional enzyme? (6)

Answer 7

-change in DNA base seq
-change in 1’ of enzyme
-change in H/I/D bonds
-change in 3’
-change in active site
-no E.S complexes form

Question 8

What type of mutation causes chromosomes to double in cells and why? (3)

Answer 8

-non-disjunction
-chromosomes don’t seperate
-in meiosis