Which term describes the order of fully aquatic mammals such as whales and dolphins?

Which term describes the order of fully aquatic mammals such as whales and dolphins?

• A. Chordata
• B. Cetacea
• C. Cnidaria
• D. Drag

Answer: (B)

Taxonomic classification places fully aquatic mammals such as whales and dolphins in the order Cetacea. In taxonomy, Cetacea is an order within the class Mammalia and includes two main groups: baleen whales (Mysticeti) and toothed whales (Odontoceti). This grouping reflects their shared evolutionary lineage and adaptations for life in the ocean, rather than broad phylum-level traits. The other terms are not the correct taxonomic rank for these animals: Chordata is a higher-level phylum that includes all animals with a notochord, Cnidaria is a separate phylum (jellyfish, corals), and Drag isn’t a biological group.

Taxonomic classification places fully aquatic mammals such as whales and dolphins in the order Cetacea. In taxonomy, Cetacea is an order within the class Mammalia and includes two main groups: baleen whales (Mysticeti) and toothed whales (Odontoceti). This grouping reflects their shared evolutionary lineage and adaptations for life in the ocean, rather than broad phylum-level traits. The other terms are not the correct taxonomic rank for these animals: Chordata is a higher-level phylum that includes all animals with a notochord, Cnidaria is a separate phylum (jellyfish, corals), and Drag isn’t a biological group.