Major highlights of Human Genome Project

 Major highlights of Human Genome Project:-

The most important feature of a DNA molecule are the nucleotide sequences, and the identification of genes and their activities. 

• Approximately 1.1% to 1.5% of the genome codes for proteins.
• The number of protein coding genes is in the range of 30,000-40,000.
• An average gene consists of 3000 bases, the sizes however vary greatly. Dystrophin gene is the larget known human gene with 2.4 million bases.
• Approximately 24% of the total genome is composed of introns that split the coding regions (exons), and appear as repeating sequences with no specific functions.
• The draft represents about 90% of the entire human genome. It is believed that most of the important parts have been identified.
• The remaining 10% of the genome sequences are at the very ends of chromosomes (i.e. telomeres) and around the centromeres.
• Chromosome 1 contains the highest number of genes (2968), while the Y chromosome has the lowest. Chromosomes also differ in their GC content and number of transposable elements.
• About 100 coding regions appear to have been copied and moved by RNA-based transposition (retro transposons).
• A vast majority of the genome (~97%) has known functions.
• More than 3 million single nucleotide polymorphisms (SNPs) have been identified.
• About 200 genes are close to that found in bacteria.
• Genes and DNA sequences associated with many diseases such as breast cancer, muscle diseases, deafness and blindness have been identified.
• Human genome is composed of 3200 Mb (or 3.2 Gb) i.e. 3.2 billion base pairs (3,200,000,000).
• Human DNA is about 98% identical to that of chimpanzees.
• Repeated sequences constitute about 50% of the human genome.
• Between the humans, the DNA differs only by 0.2% or one in 500 bases.