How many clades does the Bilateria comprise?Multiple choice question.FourOneTwoThree

To answer the question regarding how many clades the Bilateria comprises, we need to analyze the options provided.

Understanding Bilateria

Bilateria is a major group of animals that are characterized by bilateral symmetry and includes a vast number of organisms. It can be divided into additional groups known as clades.

Breakdown of Options

1. Four
2. One
3. Two
4. Three

Analysis

Bilateria is generally divided into three main clades, which are:

1. Deuterostomia: This clade includes species like chordates (vertebrates) and echinoderms (like starfish).
2. Protostomia: This clade is further divided into two significant subclades:
   • Ecdysozoa (which includes arthropods and nematodes)
   • Lophotrochozoa (which includes mollusks and annelids)

Thus, considering the standard classifications in biology, Bilateria is traditionally recognized to comprise three primary clades: Deuterostomia and two subclades under Protostomia.

Final Answer

Three clades.