Question

Identify the stinging cells abundant in the tentacles of the hydra.

• A. Ctenidia
• B. Cnidoblasts
• C. Ostia
• D. Ganglia

Answer 1

The correct option is B

Cnidoblasts

The correct option is B.

Explanation of correct option:

1. Hydra belongs to the phylum Cnidaria.
2. Special stinging cells called cnidoblasts are present in the body and are abundant in tentacles.
3. They help in paralyzing the prey.

Explanation of incorrect options:

Option A:

1. The gills of the molluscs are called ctenidia.
2. They are located in the mantle cavity.
3. Ctenidia helps in respiration and increases the space inside the body of molluscs.

Option C:

1. Pores present on the porous body of the sponges are called Ostia.
2. Ostia allows the entry of water inside the sponges.

Option D:

1. In organisms belonging to the phylum Annelida, the nervous system consists of a nerve ring and a solid ventral nerve cord with ganglia.
2. A ganglion is a bundle of nerve cells.
3. A nerve ring and a solid ventral nerve cord with ganglia form the primitive brain.

Final answer: Cnidoblasts are the stinging cells abundant in the tentacles of the hydra.