Genes and proteins in health and disease

Question 1

What are proteins made up from?

Answer 1

Chains of amino acids called polypeptides

Question 2

What are mutations?

Answer 2

Are changes in the DNA that can result in no protein or an altered protein being synthesised

Question 3

What can mutations do?

Answer 3

Alter genes or chromosomes

Question 4

What does a single gene mutation affect?

Answer 4

It affects the DNA nucleotide sequences and include deletion, insertion and substitution of nucleotides

Question 5

What does a nucleotide insertion or deletion result in?

Answer 5

A frameshift mutation or expansion of a nucleotide sequence repeat

Question 6

What are mutations important for

Answer 6

Evolution

Question 7

What can a regulatory sequence mutation alter?

Answer 7

Gene expression

Question 8

What can a chromosome mutation be described as?

Answer 8

Lethal

Question 9

What are the single gene mutations?

Answer 9

Substitution- minor missense major, nonsense
Insertion- major, frameshift
Deletion- major, frameshift

Question 10

What is a substitution single gene mutation?

Answer 10

A Dna nucleotide base is removed and another is added to the DNA sequence

Question 11

What is an insertion single gene mutation?

Answer 11

Additional nucleotide added into a DNA sequence

Question 12

What is a deletion single gene mutation?

Answer 12

Nucleotide removed from a DNA sequence but not replaced with another

Question 13

What is the effect of a gene mutation?

Answer 13

It changes the base order within a gene and so alters the amino acid sequence of the protein coded for

Question 14

What is the effect of a chromosome mutation?

Answer 14

Affects the structure or number of chromosome present in cells

Question 15

An example of a splice site mutation

Answer 15

An intron being left in the mature RNA and so contributing to protein structure,
it would result in an altered protein that would not function normally

Question 16

What is a missense?

Answer 16

One amino acid being changed for another.

This may result in a non-functional protein

Question 17

What is a nonsense?

Answer 17

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

Question 18

What does a frameshift mutation do?

Answer 18

Cause all of the codons and all of the amino acids after the mutation to be changed
Major effect on the structure

Question 19

What are the chromosome mutations?

Answer 19

Duplication,deletion, Inversion,translocation

Question 20

What are deletion chromosome mutations?

Answer 20

Where a section of a chromosome is removed, make them lethal

Question 21

What are Inversion chromosome mutations?

Answer 21

Where a section of chromosome is reversed. make them lethal

Question 22

What are translocation chromosome mutations?

Answer 22

A section of a chromosome is added to a chromosome, no its homologous partner,make them lethal

Question 23

What is the result of a splice site mutation?

Answer 23

some intorns being retained or some exons not being included in the mRNA transcript

Question 24

Describe the effects of deletion mutations on the structure of the polypeptide coded for by the original gene

Answer 24

Gives a frameshift mutation effects with major changes to amino acid sequence or all amino acid changed after mutation

Question 25

Describe the effects of substitution mutations on the structure of the polypeptide coded for by the original gene

Answer 25

Results in missense and gives minor changes to polypeptide or only one amino acid changed or result in nonsense if stop codon affected