Some researchers claim that sponge genomes have homeotic genes, but no Hox genes. If true, this finding would ________.
A) mean that sponges must no longer be classified as animals
B) confirm the identity of sponges as "basal animals"
C) mean that extinct sponges must have been the last common ancestor of animals and fungi
D) require sponges to be reclassified as choanoflagellates

Question

Quizplus · Accepted Answer

The presence of homeotic genes but no Hox genes supports the idea that sponges are "basal animals" and likely diverged from the animal lineage before the evolution of Hox genes, which are important in determining body plan in more complex animals. It does not affect their classification as animals. The absence of Hox genes also does not necessarily mean that extinct sponges were the last common ancestor of animals and fungi, nor does it require sponges to be reclassified as choanoflagellates.

Some Researchers Claim That Sponge Genomes Have Homeotic Genes, but No