Which term denotes the class that includes humans and whales?

Which term denotes the class that includes humans and whales?

• A. Hermatypic
• B. Holothuroidea
• C. Invertebrate
• D. Mammalia

Answer: (D)

Classification by class groups organisms that share key vertebrate traits. Humans and whales are both vertebrates in the phylum Chordata, and they share defining features of mammals: they are warm-blooded, have hair at some stage, and females produce milk to feed their young. These shared characteristics place them in the class Mammalia. The other terms describe different groups: hermatypic refers to reef-building corals, holothuroidea are sea cucumbers (a class of echinoderms), and invertebrate means lacking a backbone, which does not apply to humans or whales. So Mammalia best identifies the group that includes humans and whales.

Classification by class groups organisms that share key vertebrate traits. Humans and whales are both vertebrates in the phylum Chordata, and they share defining features of mammals: they are warm-blooded, have hair at some stage, and females produce milk to feed their young. These shared characteristics place them in the class Mammalia. The other terms describe different groups: hermatypic refers to reef-building corals, holothuroidea are sea cucumbers (a class of echinoderms), and invertebrate means lacking a backbone, which does not apply to humans or whales. So Mammalia best identifies the group that includes humans and whales.