Scientists believe that ancient ancestors of all animals were.
ASingle-celled prokaryotes that reproduced asexually
BSingle-celled eukaryotes that sometimes grew in colonies
CMulti-cellular organisms that were probably autotrophic.
DMulti-cellular organisms with an alternation of generations lifecycle.
ASingle-celled prokaryotes that reproduced asexually
BSingle-celled eukaryotes that sometimes grew in colonies
CMulti-cellular organisms that were probably autotrophic.
DMulti-cellular organisms with an alternation of generations lifecycle.