9.1 gene mutation

Question 1

what is mutation?

Answer 1

any change to the quantity / base sequence in the DNA of an organism

Question 2

when does inherited mutation occur?

Answer 2

gamete formation (sudden & distinct differences)

Question 3

when does gene mutation occur?

Answer 3

arises spontaneously during DNA replication

Question 4

what will a base deletion mutation result in?

Answer 4

frameshift to the left & leads to different amino acid sequences

Question 5

what are the 3 outcomes of a base substitution mutation?

Answer 5

1) nothing occurs (same amino acid coded due to degenerate code)
2) codes for different amino acid
3) codes for stop codon -> stops mRNA translation -> no functional polypeptide

Question 6

what is chromosome mutation?

Answer 6

changes in structure / number of chromosomes which could arise spontanously

Question 7

give an example of chromosome mutation.

Answer 7

down syndrome: extra chromosome 21
- non-disjunction of homologous pairs during meiosis