1.4

Question 1

what is a single-gene mutation

Answer 1

•when a DNA nucleotide sequence is altered in one particular gene on a chromosome

Question 2

what are the 3 types of (point)
single-gene mutations

Answer 2

•substitution
•insertion
•deletion

Question 3

describe the point mutation insertion

Answer 3

•one nucleotide is inserted into the DNA strand

Question 4

describe the point mutation deletion

Answer 4

•one nucleotide is removed from the DNA strand

Question 5

describe the point mutation substitution

Answer 5

•one nucleotide is replaced with another in the DNA strand

Question 6

what is a frameshift mutation

Answer 6

•caused by the insertion or deletion mutation

•all codons and amino acids from the mutation onwards are altered
-polypeptide/protein structure is majorly affected

Question 7

what does substitution mutations further break down into?

Answer 7

•missense mutations
•nonsense mutations

Question 8

describe a missense mutation

Answer 8

•one codon and amino acid is altered

•has little effect on the polypeptide/protein
or
•could produce a non-functional protein

Question 9

describe a nonsense mutation

Answer 9

•one codon is altered and becomes a stop codon

•translation stops prematurely and protein is shorter and non-functional

Question 10

describe a splice-site mutation

Answer 10

•caused by a substitution mutation at a splice-site (where an intron is cut during RNA splicing)

•polypeptide/protein will have extra or missing amino acids

Question 11

what is a chromosome structure mutation

Answer 11

•change in the structure of one or more chromosomes which changes the number or sequence of genes in that chromosome

Question 12

what are the 4 types of a chromosome structure mutation

Answer 12

•inversion
•deletion
•duplication
•translocation

Question 13

describe the inversion mutation

Answer 13

•a section of the chromosome is reversed

Question 14

describe a deletion mutation

Answer 14

•a section of the chromosome is removed

Question 15

describe a duplication mutation

Answer 15

•a section of one chromosome is removed and joins onto its homologous partner

Question 16

what mutations does a translocation mutation break down into?

Answer 16

•reciprocal
•non-reciprocal

Question 17

describe a non-reciprocal translocation mutation

Answer 17

•a section of one chromosome is removed and joins onto another chromosome which is not its homologous partner

Question 18

describe a reciprocal translocation mutation

Answer 18

•sections from two different chromosomes are removed which switch places and join onto the opposite chromosome