Question

Cockroach has a stomodeal valve between
(a) Crop and gizzard
(b) Gizzard and mesenteron
(c) Mesenteron and ileum
(d) Ileum and colon

Answer 1

Hint: It is muscular and a bulb-like structure internally provided with thick cuticles forming six highly chitinous plates called teeth. Cuticle teeth help in crushing the food particle. The entire foregut is lined by the cuticle.

Complete Step by Step Answer:
- Midgut (mesenteron or ventriculus) is a short, tubular line with glandular endoderm.
- Stomodeal valve Of cockroach is called proventriculus or gizzard ard. It is a membrane growth present In the stomach of a cockroach lies between the gizzard and midgut.
- Its function is to prevent the entry of the food from the midgut into the gizzard. Thus, it prevents the backflow of mixed food into the gizzard.

- The food bolus in the mesenteron is enveloped by a porous, mesh-like membrane called peritrophic membrane which is secreted by the glandular cells of the anterior part of the mesenteron. From the hard food particles, the peritrophic membrane protects the wall of the mesenteron.
So, the correct answer is, ”Gizzard and mesenteron”.

Additional information:
- The alimentary canal of a cockroach is long and coiled, divided into three main parts namely foregut, midgut, and hindgut.
- Foregut is divided into five parts: Buccal chamber, pharynx, esophagus, crop, and gizzard
- At the anterior end of the mesenteron there are eight blind glandular hepatic caecae that secretes digestive enzymes.
- A cockroach is omnivorous and feeds on all sorts of organic debris. Zymase and amylase are the digestive enzymes of saliva.

Note:
- Most of the food’s nutrition is digested in the crop.
- The food which gets digested is absorbed in mesenteron.
- Crop is meant for storing food and Gizzard is meant for grinding and straining of food.