Question

The current estimate of the number of genes in the human genome is:


1000


24,000


100,000


50,000

Answer 1

B

Answer 2

The Human Genome Project has revealed that there are probably about 20,000-25,000 'haploid' protein coding genes. The completed human sequence can now identify their locations. But only about 1.5% of the genome codes for proteins, while the rest consists of non-coding RNA genes, regulatory sequences, introns, and noncoding DNA (once known as "junk DNA").

Surprisingly, the number of human genes seems to be less than a factor of two greater than that of many much simpler organisms, such as the roundworm and the fruit fly -- see table showing number of genes for different organisms.

Answer 3

humans chromosomes --diploid =46= base pairs =3.3 x 109= genome size (#genes) = ~21,000

Answer 4

So B is your answer