DNA

Question 1

Pros and cons of sanger sequencing

Answer 1

cheap
quick
highly accurate
can be difficult with large amounts of DNA

Question 2

Pros and cons of next generation sequencing

Answer 2

much faster than sanger
highly automated 
not as accurate
usually aligned to reference 
entire genome can be encoded in a few days

Question 3

Pros and cons of PCR

Answer 3

very specific, rapid, cheap
can quantify DNA
can be used to identify infection

Question 4

Pros and cons of genome wide association studies

Answer 4

analyses SNP profiles of those with and without disease
ethnic differences
can’t test for disease

Question 5

Describe applications of PCR

Answer 5

real time PCR using fluorescent dyes
identifying infection
single gene abnormality
meiosis and gene linkage studies
DNA fingerprinting

Question 6

Describe microsatellites

Answer 6

Runs of repetitive DNA
length varies among individuals
PCR can be used to amplify these and determine their length
Good way of building up markers
follow up family tree
used to determine how genes are transmitted

Question 7

Describe SNPS

Answer 7

single nucleotide polymorphisms
3 million in human genome
can be used to stratify patients
haemachromatosis is an SNP
Grouping of SNPs allows genome-wide searching

Question 8

Describe issues with population structure when carrying out genome wide association studies

Answer 8

potential confounding
must control for cases and control
repeat in different populations
statistical methods

Question 9

Describe epigenetics

Answer 9

changes not caused by changes in DNA sequence
e.g methylation or phosphorylation
Epigenetic tags should be lost before meiosis and not inherited
Bedworth Wideman syndrome - rare inheritable disease caused by epigenetic tags