3.12 - Mutations

Question 1

What are mutations?

not x-men related :)

Answer 1

• occurs when alterations are made to nucleotide squences in DNA
• they can have either a positive, negative, or no effect

Question 2

what are no effect mutations called?

Answer 2

silent mutations
- no change in amino acid code

Question 3

Mutations are classified into 2 categories. What are they?
Describe them.

Answer 3

• Point mutation: a change is only made at one point along the DNA strand so only one gene is affected
• Chromosomal mutation: a change is made to the structure and/or number of chromosomes so that multiple genes may be affected
• (on a larger/macro scale)

Question 4

What are the 3 types of point mutation?

Answer 4

1) Base substitution
2) Deletion
3) Insertion

Question 5

What is base substitution?

point mutation

Answer 5

when one nucleotide is substituted for another

Question 6

What is deletion?

point mutation

Answer 6

when a nucleotide is deleted from the gene sequence

Question 7

What is insertion?

point mutation

Answer 7

when a nucleotide is added to the gene sequence

Question 8

What is mis-sense mutation?

Answer 8

This occurs when changes in the base sequence alters a codon, resulting in a different amino acid
(may change protein structure)

Question 9

What is non-sense mutation?

Answer 9

This occurs when there is a change in the base sequence that converts a codon to a stop codon; therefore translation stops prematurely. It’s often leathal to the cell!

Question 10

What is a frame shift mutation?

Answer 10

• This occurs when there is a change in the “reading frame”.
• Every amino acid after the mutation is incorrect.
• It’s considered the most dangerous mutation & most likely yeilds an ineffective protein.