Question

(i) Name the three regions of alimentary canal of Cockroach. 

(ii) Mention the role of gizzard, hepatic caeca and malpighian tubules in the alimentary canal of Cockroach. 

(iii) How many segments are there in the thoracic region of Cockroach? 

(iv) What does paurometabolous mean with reference to Cockroach? 

(v) Why is the eye of cockroach called as compound eye?

Answer 1

(i) Fore gut, Mid gut and Hind gut 

(ii) Role of Gizzard, Hepatic caecae and Malpighian tubules are as follows: 

(a) Gizzard: The crop opens posteriorly into a small thick walled, muscular gizzard. They help in grinding the food. 

(b) Hepatic caecae: Hepatic caecae open at start of midgut and secrete many digestive enzymes-lipase, protease, peptidase, amylase, maltase, lactase, invertase and chitinase. 

(c) Malpighian tubules: The malpighian tubules help in removal of excretory products from the haemolymph. 

(iii) Three segments. 

(iv) Paurometabolous with reference to cockroach means a simple, gradual direct metamorphosis in which immature forms resemble the adult except in size and referred to as nymph. 

(v) Cockroach eyes are called compound eyes because they are made up of repeating units, the ommatidia, each of which function as a separate receptor.