Sequencing the Human Genome

Question 1

Why was the human genome sequenced?

Answer 1

To identify all human genes and their roles
To analyse genetic variation between humans

Question 2

What is a genome?

Answer 2

Complete set of DNA of an organism including all its genes

Question 3

What is a genomic?

Answer 3

The study of genomes

Question 4

Nuclear DNA vs Mitochondrial DNA

Answer 4

Nuclear : 22 autosomes, 6 billion base pairs, half from each parent, <20,000 genes
Mitochondrial : single, circular, ~17,000 base pairs, all from mother, 37 genes

Question 5

Key findings of the human genome

Answer 5

Fewer genes then expected
Less than 2% of our genome codes for proteins
Many genes still have unknown function
Any two human genomes are 99.9% similar

Question 6

Why are our genomes only 0.1% different?

Answer 6

Changes range from single base to chromosome rearrangements
Single nucleotide polymorphisms (SNP’s) are sites in the DNA that commonly vary within populations

Question 7

What are SNP’s?

Answer 7

Inherited variations - single base pair changes - mostly from parents
Single nucleotide polymorphisms

Question 8

What can analysing common variants tell you?

Answer 8

Who you’re related to
Where your ancestors came from
Muscle type
Disease risk

Question 9

What are STR’s?

Answer 9

Short Tandem Repeats
Repeats of 2-5 nucleotides found in specific regions of genome
Used to create genetic profiles or DNA fingerprints

Question 10

What are InDels?

Answer 10

Small insertions or deletions
Second most common type in human genome
Can cause ‘frame shift’ and change way DNA is read
e.g. cystic fibrosis

Question 11

What are CNV’s?

Answer 11

Copy number variations
Chunks of DNA that are present at different amounts or copy numbers relative to a reference genome
Can be deleted or duplicated and span multiple genes
Associated with sensory perception and immunity