CRM DNA

Question 1

DNA-deoxyribonucleic acid

Answer 1

coiled double helix, sugar phosphate backbone and base pairing
cyclic bases stack
G+C 3H A+T 2H base pair specificity

Question 2

automated DNA sequencing

Answer 2

rapid sequencing of complex genomes, heavily dependent on robotics and automation

Question 3

sequence assembly

Answer 3

overlapping regions identified, careful of repeat sequences
computer uses kmers, short read assemblies build up a series of contigs, order them using targeted sanger sequencing at ends of contigs

Question 4

Sanger sequencing simplified

Answer 4

dna has to be amplified, denature = complimentary strand and add primer, split into 4 tubes add DNA polymerase and all four dNTPs, specialised ddNTP then added, polymerase adds dNTPs to the primer until ddNTP terminates the sequence, results in different length DNA sequences, then separated by GEP

Question 5

Sanger vs illumina and nanopore

Answer 5

sanger accurate single reaction good for defined regions, others are error prone massively parallel (next generation) but generate whole genome

Question 6

PCR applications

Answer 6

single gene abnormality but requires knowledge of gene targets

Question 7

PCR

Answer 7

denature, primer anneal, taq polymerase(heat resistant from geysers) makes new strand with nucleotides, repeat cycle

Question 8

next gen simplified

Answer 8

DNA fragmented and 2 types adapter added (oligonucleotides)
DNA denatured and attached to flow cell
Amplification by PCR new strand is removed as not attached
adaptors bridge build and amplification but this time strand also sticks, this is repeated
now have forward and reverse strands cleave one for sequencing
primer joined, fluorescent nucleotides added and identified by laser
data analysed using overlays

Question 9

microsatellites

Answer 9

mapping diseases, labour intensive for many microsatellites

Question 10

genome wide SNP association

Answer 10

will generate possible genes is not a test (Single nucleotide polymorphisms) can identify using fluorescent markers

Question 11

epigenetics

Answer 11

heritable change not caused by changes in DNA sequence eg methylation, histones or acetylation that influence gene expression

Question 12

reprogramming is thought to remove epigenetic tags in fertilised cell

Answer 12

however some rare diseases are thought to inherit epigenetic tags

Question 13

genome wide association study

Answer 13

scans many genomes looks for genetic markers to predict presence of a disease

Question 14

epigenetic and differentiation

Answer 14

epigenetic modifications replicated in daughter cells