If a single mutation turns off the growth of some pairs of legs within an organism, what's most likely affected?
a. a hox gene
b. a duplicated gene
c. a deleted gene
d. a substituted gene

its a hox gene

Ans.

In vertebrates, limb development is performed by a group of genes, known as Hox genes (homeotic box genes). These genes act as transcription factors and initiate the process of limb development in developing embryo. The Hox genes also play role in determination of head-to-tail axis of body plan.

A single mutation in Hox genes may results in formation of defective protein that turn off the growth of leg pairs in an organism. Thus, the correct answer is option A). 'a Hox gene.'