Question

Which of the following is not a feature of the earthworm?

• A. Earthworms have a streamlined and segmented body.
• B. For easy movement through the soil, earthworms release mucus.
• C. They have open circulatory system
• D. Earthworms are sensitive to vibrations and light.

Answer 1

The correct option is C

They have open circulatory system

The correct option is C.

The explanation for the correct option:

1. An earthworm comes under the phylum Annelida.
2. It is a terrestrial invertebrate, which exhibits a tube-within-a tube body plan.
3. The earthworm possesses a closed circulatory system.
4. In earthworms, the circulation of blood takes place primarily through vessels.
5. The three prime vessels, which supply the blood to all the organs within the earthworm are dorsal blood vessels, aortic arches, and ventral blood vessels.

The explanation for the incorrect options:

Option A:

1. Earthworms exhibit soft, stream-lined, and segmented bodies.
2. They are generally brown, pink, or red and are a few inches in length.

Option B:

1. Earthworms release cutaneous mucus, that is, a lubricant, which helps in its movement via the soil.
2. The mucus safeguards the organism from being covered by soil particles.

Option D:

1. Earthworms possess no ears or eyes, however, they possess light-sensitive cells, which help them to differentiate between darkness and light.
2. Their bodies are also sensitive to vibrations.

Final answer: Open circulatory system is not a feature of the earthworm.