Surprisingly humans have less than twice as many genes as th

Surprisingly, humans have less than twice as many genes as the nematode C. elegant. despite having many more cells, more cell types, a much more complicated body plan. and much more complicated behaviors. How can this apparent paradox be explained? Be sure to include a description of the structure of the human genome in your answer.

Solution

In humans, there are nearly 22,000 protein coding genes as compared to nearly 20,000 genes of C. elegans.

In humans,there are protein coding sequences or exons that can be separated from non-coding sequences, the introns. Various different proteins can be produced through mix and match of the various exons.Many of the non-coding genes help in gene expression and regulation.

The cell locations in the human body are not predetermined precisely. The progeny of other embryonic cells take over the function if an embryonic cell is lost. This is not the case in C. elegans where development is predetermined. The body cells are always found at the same body locations. If an embryonic cell is removed from C.elegans, the body part resulting from that cell would be missing. Therefore, around 20, 000 genes are required to construct just about 1000 cells in C. elegans whereas humans with only a few more gens have a much more complicated body plan.