1. To dentify all the approximately 20,000-25,000 genes in human DNA.
2. To determine the sequences of the 3 billion base pairs that makes up human DNA.
3. To store this information in data base.
4. To develop improvised tools for data analysis.
5. To transfer related technologies to other sectors, such s industries.
6. To address the ethical, legal and social issues (ELSI) that may arise from the project.
1. The human genome contains 3164.7 million nucleotide bases.
2. The average gene consists of 3000 bases, but gene size vary greatly (the largest human gene is dystrophin containing 2.4 million bases).
3. The total number of f genes in the genome is estimated at 30,000 and all (99.9 percent) nucleotide bases are exactly the same in all people
4. Functions of about 50% of the discovered genes are still unknown.
5. Less than 2% of the genes of the genome codes for proteins.
6. Chromosome 1 has most genes (2968) and the Y has the fewest (231) 100%
7. Repeated sequences (AT-AT-AT or GC-GC-G…… make up very large portion of the human genome.
8. Scientists have identified about 1.4 million locations where single base DNA differences (SNPs- single nucleotide polymorphism, pronounced as ‘snips’) occur on humans.
DNA fingerprinting was invented in 1984 by Professor Sir Alec Jeffreys after he realised you could detect variations in human DNA.
DNA fingerprinting is a method used to identify an individual from a sample of DNA at unique patterns in their DNA.
Seven steps to understanding DNA fingerprinting:
1. Extracting the DNA from cells.
2. Cutting up the DNA using an enzyme.
3. Separating the DNA fragments on a gel.
Transferring the DNA onto paper.
4. 5. Adding the radioactive probe.
6. Setting up the X-ray film.
7. Observe the dark bands.
1. The first step of DNA fingerprinting was to extract DNA from a sample of human material, usually blood.
2.Molecular ‘scissors’, called restriction enzymes, were used to cut the DNA. This resulted in thousands of pieces of DNA with a variety of different lengths.
3 . These pieces of DNA were then separated according to size by a process called gel electrophoresis.
1. An electric current was applied which pulled the negatively charged DNA through the gel.
2. The shorter pieces of DNA moved through the gel easiest and therefore fastest. It is more difficult for the longer pieces of DNA to move through the gel so they travelled slower.
3. As a result, by the time the electric current was switched off, the DNA pieces had been separated in orden of size. The smallest DNA molecules were furthest away from where the original sample was loaded on to the gel.
4. Once the DNA had been sorted, the pieces of DNA were transferred or ‘blotted’ out of the fragile gel on to a robust piece of nylon membrane and then ‘unzipped’ to produce single strands of DNA.
5. Next the nylon membrane was incubated with radioactive probes.
6. The probes only attach to the pieces of DNA that they are complementary to in this case they attach to the minisatellites in the genome. This is called hybridization. They are observed as dark bands on x ray films.