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0

What are the three types of single nucleotide changes?

Mutations that change gene products
Mutations that change the amount of gene product
Mutations that change the polypeptide length

1

Define a transition

A mutation to the same type of base.
E.g. Pyrimidine to pyrimidine

2

What is a transversion?

Mutation to a different type of base, so a purine converted to a pyrimidine.

3

What are the 4 subunits of Heamoglobin?

2 alpha
2 betw

4

What chromosome is the gene that encodes the alpha subunits of heamoglobin located on?

Chromosome 16

5

Which chromosome is the gene that encodes the beta subunit of heamoglobin located on?

Chromosome 11

6

Who discovered sickle cell aneamia and when?

James herrick in the 1920s

7

What are the symptoms of sickle cell aneamia?

Susceptible to infection
Aneamia is acute when oxygen is limited
Red blood cells sickle
HbA precipitates in low levels of oxygen

8

What mutation causes sickle cell aneamia?

A glutamate to a valine on gene 6 of the beta polypeptide chain of heamoglobin.
(Remember codon 7 = amino acid 6)

9

What is the name of diseases caused by mutations in the beta-globin gene?

Haemoglobinopathies

10

How do mutations reduce gene expression by affecting transcription or translation?

Alter promoter activity
Alter translation initiation at AUG
Prevent mRNA splicing
Reduce mRNA stability

11

How is Hb Leiden caused?

The beta chain of haemoglobin is 1 amino acid shorter than normal

12

What mutation causes Hb Lyon?

The beta chain is 2 amino acids shorter than normal

13

What mutation causes Hb Gun-Hill?

The beta chain of Hb is 5 amino acids shorter than normal

14

What is a chain termination mutation?

Base substitution that changes a sense codon into a stop codon. These can make the chain longer or shorter.

15

What does a frameshift mutation cause?

Single base additions/deletions

16

Who discovered transposable element insertions?

Barbara McClintock

17

What are transposable element insertions?

They are specific DNA sequences which are supernumerary and always contained within another DNA molecule. They move as a discrete unit to random sites.