Mutations

Question 1

definition of Mutation:

Answer 1

random changes to DNA sequences

Question 2

what is a single gene mutation?

Answer 2

a change in a DNA nucleotide sequence in one gene.

Question 3

what is meant by a missense mutation?

Answer 3

one amino acid being changed for another. may result in a non-functional protein or have little effect on the protein.

Question 4

what is meant by a nonsense mutation?

Answer 4

premature stop codon being produced which results in a shorter protein.

Question 5

what is meant by a splice site mutation?

Answer 5

some introns being retained and/or some exons not being included in the mature transcript.

Question 6

examples of single gene mutations:

Answer 6

insertions, deletion, substitution

Question 7

examples of nucleotide substitutions:

Answer 7

missense, non-sense, splice-site.

Question 8

examples of nucleotide substitutions in insertion and deletion:

Answer 8

frame-shift mutation.

Question 9

what is meant by a frame-shift?

Answer 9

after the mutation it causes all the codons and amino acids to be changed.

Question 10

examples of chromosomes mutations:

Answer 10

duplication, deletion, inversion, translocation.

Question 11

what happens in: 
duplication
deletion
inversion
translocation

Answer 11

1. where a section of chromosome is added from its homologous partner
2. where a section of chromosomes is removed
3. where a section of chromosome is reversed
4. where a section of chromosome is added to a chromosome but not its homologous partner

Question 12

how are mutations beneficial for evolution?

Answer 12

duplication allows potential beneficial mutations to occur in duplicated a gene, while the original gene can still be expressed to produce protein.