Question

The characters of jellyfish include
(A) Typically have a radial symmetry
(B) Have head and mouth
(C) Triploblastic tissue organization
(D) Have specialized cells called nematocysts

• A. (A), (C) and (D) only
• B. (A), (B) and (D) only
• C. (A), (B), (C) and (D)
• D. (A) and (D) only

Hint:

A defining feature of the Phylum Cnidaria (which includes jellyfish, anemones, and corals) is their diploblastic body plan.
They also possess unique stinging structures called nematocysts.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Jellyfish belong to the Phylum Cnidaria (Class Scyphozoa).
Cnidarians are primitive aquatic animals characterized by tissue-level organization and specialized stinging cells.

Step 2: Detailed Explanation:
Let us evaluate each biological character:
- (A) Radial Symmetry: Cnidarians are radially symmetrical, meaning their body parts are arranged symmetrically around a central oral-aboral axis. This is true.
- (B) Head and Mouth: Jellyfish possess a central mouth surrounded by tentacles, but they lack cephalization (no distinct head or brain). This statement is false.
- (C) Triploblastic tissue organization: Cnidarians are diploblastic, consisting of only two embryonic germ layers: ectoderm (epidermis) and endoderm (gastrodermis), separated by an extracellular mesoglea. They are not triploblastic. This statement is false.
- (D) Nematocysts: Cnidarians possess specialized stinging structures called nematocysts (contained within cnidocytes) used for prey capture and defense. This is true.
Therefore, only characters (A) and (D) apply to jellyfish.

Step 3: Final Answer:
The correct combination is (A) and (D) only.