Question

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.

Answer 1

c. confirm the identity of sponges as "basal animals."

Step-by-step explanation:

Homeotic genes (also known as homeobox genes) are genes that encode major transcription factors found in divergent species ranging from animals to plants. These genes contain an evolutionarily conserved sequence (homeobox sequence) that encodes a 60-amino acid DNA-binding domain (homeodomain) found in major transcription factors that interact with DNA and thus control body patterning during development of plants and animals. Moreover, Hox genes are a subset of homeotic genes only found in bilaterian animals that have arisen more recently in evolution. In animal embryo development, Hox genes control the body pattern along the head–tail axis.