Mutations

Question 1

Causes of mutations

Answer 1

• exposure to radiation,
• viruses,
• faulty copying during transcription

Question 2

A change in the sequence of nucleotides in DNA

Answer 2

Mutation

Question 3

Mutation

Answer 3

Change in the sequence of nucleotides in DNA

Question 4

Types of mutations

(EXTENSION)

Answer 4

• Point: single nucleotide change
• Substitution: replacing one (or more) nucleotide(s) with another
• Deletion: deleting one (or more) nucleotide(s) from the DNA
• Insertion: adding one (or more) nucleotide(s) into the DNA

Question 5

The effect of a mutation could be…

Answer 5

• beneficial - the change results in a new adaptation that makes the organism better suited to its environment (natural selection will favour this mutation)
• neutral - no change as the same amino acid is coded for
• harmful - the change results in a different protein, or no protein, being produced, which is harmful to the organism lethal - the change results in a non-viable cell/ zygote/ organism, which therefore dies.

Question 6

True or false: mutations are always harmful

Answer 6

False

Question 7

Frame shift

(EXTENSION)

Answer 7

A change in the way codons are read because nucleotide triplets shift as a result of a deletion or insertion

Question 8

Mutation (definition)

Answer 8

The alteration of the nucleotide sequence of the genome of an organism