Salient features of human genome

(i) The human genome contains 3164.7 million nucleotide bases.

(ii) The average gene consists of 30000 the largest know human gene being dystrophin at 2.4 million base.

(iii) The total number of genes is estimated to be 30000 and 99.9% nucleotide bases are exactly the same in all people.

(iv) The functions are unknown for over 50% of the discovered genes.

(v) Less than 2% of the genome codes for proteins.

(vi) The human genome contains large repeated sequences.

(vii) The repeated sequence is thought to have no direct coding functions but they throw light on chromosome structures, dynamics and evolution.

(viii) Chromosome l has most genes (2968) and the Y has the fewest genes (231).

(ix) Scientists have identified about 1.4 million locations where single-base DNA sequence differences called SNPs or Single Nucleotide Polymorphisms occur in humans.