Identify the incorrect feature of human genome.

The correct answer is Option (2) → More than 8 percent of the genome codes for proteins.

The Human Genome Project (HGP) found the sequence of all the bases in human DNA and drew a set of salient observations from it.

Option (1) The average gene consists of 3000 bases, but sizes vary greatly, with the largest known human gene being dystrophin at 2.4 million bases. — A correct feature of the human genome. Genes are not of one size. Dystrophin is about 800 times longer than an average gene.

Option (2) More than 8 percent of the genome codes for proteins. — An incorrect feature of the human genome. The coding part is less than 2 per cent, not more than 8 per cent. Most of the genome does not code for proteins; much of it is made of repeated sequences.

Option (3) Repeated sequences make up very large portion of the human genome. — A correct feature of the human genome. These stretches of DNA are repeated hundreds to thousands of times. They have no direct coding function, but they help us understand the structure and evolution of chromosomes.

Option (4) Almost all (99.9 per cent) nucleotide bases are exactly the same in all people. — A correct feature of the human genome. People differ in only about 0.1 per cent of their bases. These small differences make each person unique and are the basis of DNA fingerprinting.

NCERT Extract:
Salient Features of Human Genome – …