Question

Which of the following is/are characteristic feature(s) of Brachiopods?

• A. Valves equilateral
• B. Inequivalved
• C. Plane of symmetry between valves
• D. Presence of ligaments

Hint:

Brachiopods are typically characterized by inequivalved shells, though some species may have relatively equilateral shells. This feature distinguishes them from other groups like bivalves.

Answer 1

The Correct Option is A, B

Step 1: Identifying Brachiopod Characteristics.
- Valves equilateral: Correct. Although brachiopods are generally inequivalved, there are some species where the valves appear relatively equal in size or equilateral. However, in most brachiopods, one valve is larger than the other, so this option may be true in some specific cases, but not a defining feature for all brachiopods.
- Inequivalved: Correct. Brachiopods are typically inequivalved, meaning that one valve is larger and more convex than the other. This characteristic is one of the most significant for brachiopods.
- Plane of symmetry between valves: Incorrect. This feature is typically found in bivalves (which have symmetry between the two valves), but not in brachiopods. Brachiopods do not exhibit this plane of symmetry between their valves.
- Presence of ligaments: Incorrect. While brachiopods do possess ligaments, they are not a distinctive characteristic of the group as a whole. Ligaments are found in many shelled organisms and do not serve as a unique feature for brachiopods.
Thus, the correct answer is (A) and (B).
Final Answer: \[ \boxed{(A), (B)} \]