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

Ans.

In vertebrates, genes responsible for the growth and development of limbs in developing embryos are known as Hox genes (homeotic-box genes). Along with limb development, these genes include a group of genes that control the head-tail axis and body plan of developing embryo.

A single mutation in a Hox genes can lead to formation of mutated Hox protein and turn off the growth of legs in an organism.

Thus, the correct answer is 'option B). a Hox gene.'

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.