Human Molecular Genetics 1

Question 1

Why was human genome sequenced

Answer 1

Identify all human genes and their roles
Analyse genetic variation between humans
Develop new sequencing techniques and computational analysis
Share genome information with the general public as fast as possible

Question 2

Summarise nuclear DNA

Answer 2

22 autosomes, X and Y
6 billion base pairs
Half from each parent
Just under 20000 genes

Question 3

Summarise mitochondrial DNA

Answer 3

Singular, circular
16569 base pairs
All from mother
37 genes

Question 4

Summarise the key findings of the human genome

Answer 4

There are fewer genes than expected
Less than 2% if our genome codes for proteins
Genome is dynamic
Still do not know what many of our coding proteins do
Most human genes are related to those of other animals
All humans are 99.9% similar at sequence level

Question 5

What percent of the genome is coding, and what is meant by exon

Answer 5

Less than 2%
Exon is a sequence of DNA that produces a corresponding sequence of mRNA

Question 6

What percent of the genome are introns, define introns

Answer 6

Intron is a region that resides within gene, but does not end up in final mature mRNA molecule (not transcribed)
20%

Question 7

What percent of genes still have unknown function

Answer 7

20%

Question 8

What are SNP’s, and how many between human genome and Watsons genome

Answer 8

Single nucleotide polymorphisms “SNPs” are sites in the DNA that commonly vary within the population
1.9 million SNP’s between human genome and Watsons genome

Question 9

Outline the features of single nucleotide polymorphisms

Answer 9

Common, about 1 in every 300 nucleotides
Mostly from parents
Many SNP’s don’t do anything, they are just inherited variations

Question 10

What can analysing common variants (genotyping) tell you

Answer 10

Who you are related too
Where some of your ancestors are from
Disease risk/association (masked data outside of USA)
If you will loose your hair
Your muscle type
How you may respond to drugs

Question 11

What are STR’s

Answer 11

Short tandems repeats and DNA profiling
Repeats of 2-5 nucleotides, found in specific region of genome
Each person inherits 2 alleles, one from each biological parent, which can differ in lengths
They can be used to create genetic profiles, or DNA fingerprints

Question 12

What are inDels

Answer 12

Small insertions or deletions
Second most common variant type in human genome
Cystic fibrosis (one of most common human genetic diseases) caused by CFTR deltaF508 - a 3 nucleotide deletion
Deletions/insertions cause reading frame shift, altering the way DNA is read downstream of mutation
200,000 InDels between human genome and Watsons genome

Question 13

What are CNVs

Answer 13

Copy number variations
Chunks of DNA >500 base pairs that are present at different amounts, or copy numbers relative to a reference genome
Can be deleted or duplicated
Humans have 10,000 CNV’s, found within and between genes
Many genes found in CNV are associated with sensory perception and immunity
23 large CNV between human genome and Watsons genome