module 6 - 21.2 DNA sequencing and analysis & 21.3 Using DNA Sequencing

Question 1

What is DNA sequencing?

Answer 1

The process of determining the precise order of nucleotides within a DNA molecule

Question 2

What processes are involved in the sequencing of a genome?

Answer 2

• DNA is chopped into fragments and each fragment is sequenced
• process incomes terminator bases, modified versions of me 4 nucleotide bases (a,t,c,g) which stop DNA synthesis at the location that an A base would se added.

Question 3

What is the sequencing process?

Answer 3

1. DNA for sequencing is mixed with a primer, DNA polymerase, an excess of normal nucleotides and terminator bases
2. Mixture placed in thermal cylinder that rapidly changes temp. at intervals in repeated cycles - at 96°C double strand separates to single strand, at 50°C primers recombine to DNA strand
3. at 60°C, DNA polymerase starts to build up new bra strands by adding nucleotides with complementary base to single strand DNA template.
4. when terminator base is added instead of normal base, synthesis of DNA is terminated as no more bases can be added - this causes many DNA fragments being different lengths depending on where terminating base is added. DNA fragments are separated by length by capillary sequencing and lasers detect different colours and order of sequence
5. Order of bases in capillary tubes shows sequence of new, complementary stand of DNA made. The data from sequencing process is fed into a computer mat reassembles the genomes by comparing all the fragments and finding areas of overlap.
6. Once a genome is assembled, scientists identify genes or pars a genome that code for specific characteristics

Question 4

What is next generation sequencing?

Answer 4

• Instead of using cell er capillaries, the sequencing reaction rakes place on a plastic side (flow gel)
• sequencing process still uses principle of adding a coloured terminator base to stop the reaction

Question 5

What is massively parallel sequencing?

Answer 5

The technique of all the clusters are being sequenced and imaged at the same time (sometimes referred to as next-generation sequencing)

Question 6

What is the process of massively parades sequencing?

Answer 6

• Integrated with computer technology
• is constantly being refined and developed
• 3 billion pairs of the human genome can be sequenced in days and those of bacteria in less than 24 hours

Question 7

What has the development of DNA profiling and DNA sequencing led to?

Answer 7

Led to the development of new areas of bioscience that help us analyse and understand, and make use of the data generated

Question 8

What is bioinformatics?

Answer 8

The development of the software and computing tools needed to organise and analyse raw biological data

Question 9

What is computational biology?

Answer 9

The study of biology using computational techniques (especially analysis of huge amounts of biodata)

Question 10

What is computational biology used for?

Answer 10

Uses data from bioinformatics to build theoretical models of biological systems which can be used to predict what happens in different circumstances.

Question 11

What is an example of the importance of computational biology?

Answer 11

• It is important in the analysis of the data from sequencing the billions of base pairs of DNA, for working out the 3D structures of proteins and understanding molecular pathways

Question 12

What does computational biology help us with?

Answer 12

Helps us to use the information from DNA sequencing eg identifying genes linked to specific diseases.

Question 13

What can computers do in biology?

Answer 13

They con compare & analyse genomes of many individuals, revealing patterns in the DNA we inherit and the diseases to which we ave vulnerable

Question 14

What can computers do in biology?

Answer 14

They con compare & analyse genomes of many individuals, revealing patterns in the DNA we inherit and the diseases to which we ave vulnerable

Question 15

What does analysing the genomes of patrollers enable?

Answer 15

• doctors to find out the source of an infection
• doctors to identify antibiotic- resistant strains of bacteria, ensuring that antibiotics are only used when they will be effective and helping prevent spread of antibiotic resistance.
• scientists to track the progressof an outbreak of a potentially serious disease and monitor potential epidemics.
• scientists to identify regions in the genome oz pathogens that may be useful targets in the development of new dugs and to identify genetic makers for use in vaccines