Table 271Proposed Number of Hox Genes in Various Extant and Extinct

Multiple Choice

Table 27.1.Proposed Number of Hox Genes in Various Extant and Extinct Animals
-All things being equal,which of these is the simplest explanation for the change in the number of Hox genes from the last common ancestor of insects and vertebrates to ancestral vertebrates,as shown in Table 27.1?

A) the occurrence of seven independent duplications of individual Hox genes
B) the occurrence of 14 independent duplications of individual Hox genes
C) the occurrence of two distinct duplications of the entire seven-gene cluster,followed by the loss of one cluster
D) the occurrence of a single duplication of the entire seven-gene cluster