The common ancestor of all animals is likely to have been a(n)______.
A) colonial, flagellated protist
B) colonial, ciliated protist
C) colonial, flagellated bacterium
D) sponge

Question

Quizplus · Accepted Answer

The most widely accepted hypothesis for the origin of animals is the colonial, flagellated protist hypothesis, which suggests that the ancestors of animals were single-celled, colonial, flagellated protists that lived in marine environments. These protists later evolved specialized cells and tissues that eventually led to the emergence of multicellular animals. There is no evidence to support the other options.

The Common Ancestor of All Animals Is Likely to Have