Question

The structure in earthworm which serves as a wedge to force open cracks in the soil is

• A. Peristomium
• B. Setae
• C. Typhlosole
• D. Prostomium

Answer 1

Answer: (D)

Prostomium

1. The first segment of the earthworm body is called peristomium or buccal segment which bears crescentic mouth. It bears a fleshly lobe-like structure called prostomium which hangs over the mouth ventrally. It is called the boring part as it bores in soil.

2. Setae are locomotory organs of earthworm.

3. Typhlosole enhances the intestinal absorption area in earthworms.

So, the correct option is 'Prostomium'.