Question

Given below are four groups (i-iv), with some examples in each. In each group there is one example that does not fit into it. Identify the odd one in each of these groups and select the correct option.
(i) Euplectella, Euspongia, Spongilla, Metridium
(ii) Physalia, Antedon, Metridium, Aurelia
(iii) Aphrodite, Asterias, Echinus, Antedon
(iv) Chiton, Pila, Euplectella, Mussels

• A. Euplectella, Antedon, Aphrodite, Mussels
• B. Metridium, Aurelia, Aphrodite, Euplectella
• C. Euplectella, Metridium, Antedon, Mussels
• D. Metridium, Antedon, Aphrodite, Euplectella

Answer 1

The correct option is D Metridium, Antedon, Aphrodite, Euplectella

In (i), Euplectella, Euspongia, and Spongella are all poriferans, while Metridium is a genus of sea anemones.

In (ii), Physalia, Metridium, and Auralia are the different genus of anemones, while Antedon is the genus of stemless crinoids that are also free-swimming.

In (iii), Aphrodite, Asterias, Echinus are examples of echinoderms, while Antedon is a genus of annelids.

In (iv), Chiton, Pila, Mussels are all molluscs, while Euplectella is a sponge.

So, the correct answer is 'Metridium, Antedon, Aphrodite, Euplectella'.