The number of legs an insect has, or the number of vertebrae in a vertebral column, or the number of joints in a digit (such as a finger) are all strongly influenced by genes.

Out of the following given choices;

A)     haploid genomes. B) introns within genes. C) heterotic genes. D) heterogeneous genes. E) Hox genes.

The answer is E. Hox genes are responsible for coding the general body plan of an animal. At embryo stage, they determine the plan from head to tail while up in the development cycle they determine the number of appendages in the animal. The sequence and function of Hox genes are highly conserved.

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