14.5: Mutations of one or a few nucleotides can affect protein structure and function

Question 1

mutations

Answer 1

alterations in the genetic material of the cell

Question 2

point mutations

Answer 2

changes in a single nucleotide pair of a gene, sickle cell disease caused by point mutation

Question 3

Base-pair substitutions

3 types ?

Answer 3

replace a single nucleotide

1. Missense Mutations: codon still codes for amino acid (not the same one)
2. Nonsense Mutations: change a regular codon to stop codon
3. Silent Mutations: Codon codes for the same amino acid

Question 4

Insertions and deletions

Answer 4

either addition or loss of nucleotide, can cause a frameshift mutation which changes all codons after mutation

Question 5

mutagens

Answer 5

Substances or forces that interact with DNA in ways that cause mutations, X-rays and Chemicals

• Spontaneous mutations can occur during DNA replication, recombination, or repair
• Induced mutations are caused by physical or chemical agents