Question

in earthworm, gizzard occurs in segment
A. 5
B. 6
C. 8
D. 10

Answer 1

Hint: Earthworm belongs to the phylum Annelida. It is a highly segmented roundworm inhabiting the soil. Gizzard is the part of the alimentary canal of the digestive system of the earthworm and it helps in the crushing of particles of soil and the decaying leaves.

Complete answer:
The earthworm is reddish-brown in color. It is a terrestrial organism that has a long cylindrical body. There are more than 100 short segments, which divide the body of earthworms.
The body wall of the earthworm is covered externally by a cuticle. The digestive system of the earthworm consists of:
Mouth- The first segment of the body is called the periosteum which contains the mouth.
Buccal cavity- The mouth opens into the buccal cavity which covers 1-3 segments.
Pharynx- The buccal cavity leads to the pharynx
Oesophagus- A small narrow tube which covers 5-7 segments.
Gizzard- It is the thick-walled organ and is the hardest part of the alimentary canal. It is used to grind up the ingested food before it is transferred to the stomach. It covers 8-9 segments.
Stomach: It covers the 9-14 segment.
Intestine- It starts from 15 segments and continues to the last
Anus- The alimentary canal opens to the exterior through the anus.

In the earthworm, the gizzard occurs in the 8th segment. So, the correct answer for the above question is option ( C ).

Note: The food of the earthworm consists of the decaying leaves and organic matter mixed up with soil and this food is ground up by the gizzard.
The epidermis of the earthworm contains secretory gland cells.