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

Question

Quizplus · Accepted Answer

The presence of homeotic genes but not Hox genes suggests that sponges belong to the earliest diverging branch of animals, known as the basal animals, which lacked the full complement of Hox genes found in most other animal groups. This finding confirms the identity of sponges as basal animals, reinforcing their evolutionary ties to other metazoans. However, it does not necessitate reclassification as choanoflagellates or exclude their status as animals.

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