alteration of the sequence of bases in DNA can alter the structure of protein

Question 1

define mutation

Answer 1

an alteration to the DNA base sequence often arising spontaneously during DNA replication

Question 2

define a gene mutation

Answer 2

changes in the base sequence or quanitity of DNA within a gene or section of DNA

Question 3

define chromosome mutations

Answer 3

changes in the structure or number in the chromosomes

Question 4

define mutagen

Answer 4

a chemical, physical or biological agent that causes mutation

Question 5

what is an insertion mutation?

Answer 5

When one base is added to the DNA sequence

Question 6

what is a deletion mutation

Answer 6

when one base is removed from the DNA sequence

Question 7

what is a substitution mutation

Answer 7

when one base is substituted with another

Question 7

what is a substitution mutation

Answer 7

when one base is substituted with another

Question 8

what is a inversion mutation

Answer 8

a sequence of bases is separated and the reattached in inverse order

Question 9

what is a duplication mutation

Answer 9

1 or multiple bases are repeated in the DNA sequence

Question 10

what is a translocation mutation?

Answer 10

where a group of bases become separated from the DNA sequence, and are then inserted into the DNA of a different chromosome

Question 11

what increases mutation rate?

Answer 11

mutagenic agents

Question 12

what may mutations result in?

Answer 12

different amino acid sequence in the encoded polypeptide

Question 13

which mutations are most likely to have a significant impact and why?

Answer 13

• insertion, deletion, duplication and translocation
• because they produce a frameshift, meaning the entire amino acid sequence produced will be different

Question 14

which mutations are less likely to have a significant impact and why?

Answer 14

• substitution and inversion
• because they only alter 1 or very few triplets, the amino acid sequence might not be affected due to the degenerate nature of the genetic code

Question 15

is a mutation resulting in a change to the amino acid sequence always harmful?

Answer 15

• No, it may be neutral if the resulting change in a protein has no effect on the organism
• may be beneficial which is the basis for evolution and natural selection

Question 16

what mutations cause a frameshift?

Answer 16

• deletion
• insertion
• duplication

Question 17

what mutations do not cause a frameshift?

Answer 17

• substitution
• inversion