21. the of animals is based on scientists’ current understanding of the evolutionary history of living species. (1 point)

The given blank can be filled with cladogram.

Explanation:

A cladogram refers to a diagram utilized by the researchers to demonstrate a phylogeny, which is considered as a hypothetical association between the groups of animals. It demonstrates groups of organisms, that is, how they are interrelated and associated with their common ancestors.  

Thus, the cladogram of animals is dependent upon scientists’ present understanding of the evolutionary history of living species.  

true, i don't really know what you're asking but from the info you provided im guessing the answer is true.

the question isn't complete here so i can't right an answer '_'