Question

What is the locomotory organ found in earthworms?

• A. Parapodia
• B. Setae
• C. Tubefeet
• D. Walking legs

Answer 1

The correct option is B

Setae

The correct answer is option B.

Explanation of correct answer:

1. Setae also called bristles is a tiny curved chitinous structures present on each segment of the earthworm.
2. Except the first, the last and clitellar segments of earthworm. It is present on each segment of the body.
3. The main function of setae is locomotion. Each seta lies in a setal sac, which is a small pit in the skin. The sac has special muscles to move the seta out or in and to bend it forward or backward.
4. It holds the ground firmly so that the other parts of the body move in the forward and backward direction.

Explanations of incorrect options:

Option A:

Parapodia is a locomotory organ present in an aquatic species like nereis which helps in swimming and respiration.

Option C:

Tube feet are sucker appendages in echinoderm that helps in moving, and gripping the substrate.

Option D:

Walking legs helps in moving, gathering the foods as well as moving water to the gills present in species like crayfish.

Final answer: Setae is the locomotory organ found in earthworms.