Question

The following are the parts of alimentary canal of cockroach and arrange them in correct sequence (anterior and posterior end)
(A) Stomodeal valve
(B) Crop
(C) Ileum
(D) Proventriculus
(E) Mesenteron
(F) Colon
A → D-B-E-A-C-F
B→ D-B-A-C-F-E
C →B-D-A-E-C-F
D → B-D-A-C-E-F

Answer 1

The digestive system of cockroach consists of alimentary canal and digestive glands. Periplaneta Americana is a common species of cockroach. They are omnivorous.
A soft, white tissue called fat body surrounds the viscera. It stores fats, glycogen and proteins.

Complete answer:
Alimentary canal of cockroach show three regions
1. Foregut (Stomodaeum)
2. Mid gut (Mesenteron)
3. Hindgut (Proctodaeum)
Foregut: An ill-defined space, the preoral cavity is enclosed by the mouth parts. Food is masticated here. It leads via mouth into a short tube pharynx that joins oesophagus. It then opens into a large pyriform sac crop, followed by hard conical gizzard (Proventriculus).
At the junction of gizzard and midgut, a stomodeal valve is present. It prevents the backflow of churned food back into the gizzard after it has reached midgut (mesenteron). It also regulate food flow.
Midgut (Mesenteron): Lined with columnar, glandular epithelium. It has hepatic caeca which secretes digestive juice.
Hindgut: It comprises a very short, narrow ileum, a long, wide, coiled colon, a short wide rectum.

Hence, the correct answer is option C.

Note: Foregut and hindgut are lined by ectodermal epithelium which secretes cuticle, midgut is lined by endodermal epithelium and lacks cuticle.

A ring of 150 fine, yellow colored thread-like Malpighian tubules joined to the beginning of ileum. They are excretory organs.
Digestive glands in midgut, hepatic caeca and salivary glands help in digestion.