Question

Which part of the alimentary canal in cockroach secretes peritrophic membrane around the food?
(a) Crop
(b) Hepatic caeca
(c) Mesenteron
(d) Gizzard

Answer 1

Hint: The endodermal cells line this part of the alimentary canal. The anterior section of this part is internally lined by the digestive juice secreting glandular epithelium. The primary site of digestion and absorption of enzyme output is this part of the alimentary canal.

Complete answer:
- The Peritrophic membrane defends the mesenteron wall from fragments of hard food.
- The oesophagus opens into a crop that is a structure similar to a sac.
- The main portion of the food canal is vegetables.
- The Gizzard is extremely muscular and shaped like a bulb. The inner wall of the gizzard produces six plates of chitinous bearing the teeth.
- Soft pads and bristles are present below the chitinous plates. They form the sieve as a structure that functions as a filtering system.
- They form the sieve as a structure that functions as a filtering system.
- Gizzard serves as a mill and extraction equipment for grinding.
- A porous, mesh - like membrane called the peritrophic membrane envelops the food bolus in the mesenteron and is secreted by the glandular cells of the anterior portion of the mesenteron.
So, the correct answer is ‘(c) Mesenteron’.

Note:
- At the gizzard-mesenteron junction, a stomodeal valve is present.
- The stomodeal valve prevents food materials from moving backward from the mesenteron to the gizzard.