Draw a neat and well labelled diagram of male reproductive system of a frog.

If the head of cockroach is removed, it may live for few days because

What external changes are visible after the last moult of a cockroach nymph?

Which one of the following has an open circulatory system?

Draw a labelled diagram of alimentary canal of a cockroach.

Describe digestive tract or alimentary canal of cockroach with diagram.