Which of the following correctly describes the major types of animals?
A) All chordates share a common ancestor, but there is no common ancestor of all invertebrates.
B) All invertebrates are chordates; vertebrates are a group that is separate from both invertebrates and chordates.
C) All invertebrates are chordates; vertebrates are a group that is separate from both invertebrates and chordates.
D) Chordates are the largest group, and it is subdivided into two groups: vertebrates and invertebrates.

I think that "A) All chordates share a common ancestor, but there is no common ancestor of all invertebrates." correctly describes the major types of animals.

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JoiePatel JoiePatel · Answer 2 · 2019-03-25T06:38:15+01:00

Answer:

The most appropriate answer would be option A.

The chordates refer to the organisms which belong to the phylum Chordata. They possess anatomical features like notochord, pharyngeal slits, dorsal nerve cord, post-anel tail, and endostyle during some period of their life cycle. They include classes amphibians, fish, reptiles, birds, and mammals. These organisms are believed to share a common ancestor.

In contrast, invertebrates refer to the organisms which lack a vertebral column. They include all the organisms other than vertebrates. For example, they include arthropods, mollusks, annelids, and cnidarians.