UNIT 1 - KA4

Question 1

What are mutations

Answer 1

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

Question 2

What is a mutation the change of

Answer 2

A mutation is a change to the genetic structure of an organism

Question 3

What is a genetic disorder

Answer 3

A genetic disorder is a condition or a disease that can be show to be directly related to an individuals genotype

Question 4

What is a chromosomal structure mutation

Answer 4

chromosomal structure mutations which involve a change in the structure of a chromosome ( this means a lot of genes are involved not just one)

Question 5

What is single gene mutation a result of

Answer 5

Single gene mutations involve the alteration of a DNA nucleotide sequence as a result of substitution , insertion or deletion of nucleotides

Question 6

What are the types of mutations all caused by substitution (single gene mutation)

Answer 6

1- missense
2- nonsense
3- splice site mutations

Question 7

Missense mutation

Answer 7

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

Question 8

Nonsense mutations

Answer 8

Nonsense mutations result in a premature stop codon being produced which results in a shorter protein

Question 9

Splice site mutations

Answer 9

Splice site mutations result in some introns being retained and/or some exons not being included in the mature transcript

Question 10

What are the frame shift mutations

Answer 10

Nucleotide insertions or deletions result in FS mutations

Question 11

What effect does frame shift mutation have on the protein

Answer 11

As a result it is highly likely that the altered protein will not be able to function properly

Question 12

What is the effect of substitution mutations compared to insertion and deletion mutations on the protein produced

Answer 12

Frame shift mutations (caused by insertion and deletion) cause all of the codons and all of the amino acids after the mutation to be changed. Whereas substitution mutations only effect a single amino acid

Question 13

What are the chromosome structure mutations

Answer 13

The mutations can be classes as : duplication, deletion, inversion and translocation

Question 14

What is deletion

Answer 14

Deletion is where a section of a chromosome is removed

Question 15

What is duplication

Answer 15

Duplication is where a selection of a chromosome is added from its homologous parter

Question 16

What is inversion

Answer 16

Inversion is where a section of chromosome is reversed

Question 17

What is translocation

Answer 17

Translocation is where a section of a chromosome is added to a chromosome, not it’s homologous partner

Question 18

What do the substantial changes in chromosome structure mutations make them

Answer 18

The substantial changes in chromosome structure mutations often make them lethal

Question 19

Why do chromosome mutations have a lethal effect

Answer 19

Chromosome mutations have a lethal effect as the changes to the genetic material are substantial (and effects a lot of genes)

Question 20

What is a single gene mutation

Answer 20

single gene mutations which involve the alteration of DNA nucleotide sequence within a single gene

Question 21

What are frameshift mutations

Answer 21

As mRNA is read as a series of codons, insertion or deletion of a nucleotide causes every codon from the site of mutation to be altered and therefore every amino acid coded for will be altered.