Which one of the following statements is not the salient feature of H…

The correct answer is Option (3) → Less than 9 per cent of the genome codes for proteins.

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 salient feature. Genes are not of one size: the average is 3000 bases, while dystrophin is about 800 times longer. The book lists this among the salient observations.

Option (2) The total number of genes is estimated at 30,000-much lower than previous estimates of 80,000 to 1,40,000 genes. — A salient feature. The gene count of about 30,000 was lower than expected.

Option (3) Less than 9 per cent of the genome codes for proteins. — Not a salient feature. NCERT says less than 2 per cent of the genome codes for proteins; the number has been changed.

Option (4) Repetitive sequences are stretches of DNA sequences that are repeated many times, sometimes hundred to thousand times. — A salient feature. Repeated sequences make up a very large part of the human genome.

NCERT Extract:
Salient Features of Human Genome – “Some of the salient observations drawn from human genome project are as follows:
(i) The human genome contains 3164.7 million bp.
(ii) The average gene consists of 3000 bases, but sizes vary greatly, with the largest known human gene being dystrophin at 2.4 million bases.
(iii) The total number of genes is estimated at 30,000–much lower than previous estimates of 80,000 to 1,40,000 genes. Almost all (99.9 per cent) nucleotide bases are exactly the same in all humans.
(iv) The functions are unknown for over 50 per cent of the discovered genes.
(v) Less than 2 per cent of the genome codes for proteins.”