Question

Arrange the given parts of a cockroach's digestive system into the correct sequence.

• A. Crop
• B. Gizzard
• C. Pharynx
• D. Malpighian tubes
• E. Hepatic caecae

Answer 1

In a cockroach, the mouth opens into the pharynx which leads to the oesophagus. The oesophagus opens into the crop which stores food before it passes to the gizzard which grinds the food particles further. At the junction of foregut and midgut, a ring of 6-8 blind tubules called hepatic or gastric caecae are present which secrete digeestive juices. At the junction of midgut and hindgut, a ring of 100-150 tubules called Malpighian tubules are present which helps in removal of excretory products from haemolymph. The hindgut is divided into ileum, colon and rectum. The rectum opens out into the anus.