Human Genome project

Question 1

What is the aim of the human genome project?

Answer 1

• To determine the order of bases in the human genome.
• To identify all genes in human genome and map their positions on chromosomes.
• To sequence the genes.
• To store the information on a database.
• To consider the ethical, social and legal issues which arise from obtaining info about the human genome.

Question 2

What is the sanger sequencing method?

Answer 2

• DNA broken into single-stranded fragments.
• Complementary strands synthesised but they were incomplete as four nucleotide triphosphates were altered. OH removed from deoxyribose, so when put into newly synthesised strand, DNA polymerase cannot bind next nucleotide so the chain terminates, last N marked with fluorescence or radioactivity, different for all four.
• From each original DNA fragment, large number of complementary strands produced, separated by gel electrophoresis, the marked nucleotide was identified.

Question 3

What does applications mean?

Answer 3

Somethings uses.

Question 4

Applications of project?

Answer 4

• Scan a patients DNA sample for mutations and compare sequence to normal version of the gene.
• Carrier screening.
• Pre-natal testing.
• Newborn baby screening.
• Screening for adult onset disorders, e.g. huntingtons.
• Forensic+identity testing.
• Greater possibility of successfully using gene therapy to correct disorders.

Question 5

Ethical concerns?

Answer 5

• Testing for late onset diseases in presently healthy individuals.
• Risks of discrimination-insurance.
• Parents may wish to scan their children, then need a decision as to when to tell.
• Lab errors, mis identification and contamination.
• Social stimatization and anxiety.
• Who should have access to this information?
• Who owns the information?
• Medical treatment or enhancement?
• Human cloning?
• Embryos can be scanned for diseases and then can be terminated if have them.

Question 6

Use of results of project?

Answer 6

• Identification of defective genes and chance of early treatment.
• Identification of genes which could make a person susceptible to certain diseases, preventative measures taken.
• Prediction of proteins that genes produce, giving opportunity to enhance or inhibit proteins by drugs.

Question 7

What is genetic counselling?

Answer 7

• Predictive diagnosis for conditions.
• Counselling before and after testing.
• Family tree drawing.
• Calculating the risk of having affected children.
• Explaining the cause.
• Quality of life.
• Availability of treatment.
• Possible options of IVF and PGD or using donor eggs.

Question 8

Sager sequencing simplified?

Answer 8

Reaction mixture contains:

• Many copies of single stranded DNA fragments.
• Free DNA nucleotides.
• Primers.
• DNA polymerase.
• Modified nucleotides carrying fluorescent markers, all different colours.

Question 9

DNA sequencing of non-human organisms?

Answer 9

Genomes are sequenced from organisms in all domains and kingdoms.
Examination of genomes closely related allows us to show evolutionary relationships, some unexpected relationships have been discovered.
e.g. research into malaria and a treatment has to continue, chemicals can be used to attack the vector and the parasite.