Question

Match the following invertebrates in Group-I with their morphological features in Group-II.

	Group-I		Group-II
P	Trilobite	1	Periproct
Q	Brachiopod	2	Hypostome
R	Bivalve	3	Deltidial plate
S	Echinoid	4	Lunule

• A. P-2, Q-4, R-1, S-3
• B. P-2, Q-3, R-4, S-1
• C. P-4, Q-3, R-1, S-2
• D. P-3, Q-2, R-4, S-1

Hint:

When matching invertebrates with features: - Trilobite → Hypostome - Brachiopod → Delthidial plate - Bivalve → Lunule - Echinoid → Periproct

Answer 1

The Correct Option is B

Step 1: Understanding the morphological features.
- Trilobite: Characterized by the presence of a hypostome, a rigid plate near the mouth used for feeding. Thus, \( P \rightarrow 2 \).
- Brachiopod: Identified by the presence of a delthidial plate, a small plate covering the pedicle opening. Thus, \( Q \rightarrow 3 \).
- Bivalve: Often shows a lunule, a depressed area in the shell near the beak. Thus, \( R \rightarrow 4 \).
- Echinoid: Has a periproct, the anal opening at the posterior end of the test. Thus, \( S \rightarrow 1 \).
Step 2: Final matching.
\[ P \rightarrow 2, \quad Q \rightarrow 3, \quad R \rightarrow 4, \quad S \rightarrow 1 \] \[ \boxed{\text{Correct option is (B)}} \]