What is the role of radula in molluscs?
The radula is a file-like rasping organ found in molluscs. It helps in scraping food. It also used for creating depression in rocks.
Which group of chordates possess sucking and circular mouth without jaws?
Cyclostomata. They are also known as the jawless fish.
Give one example each of an animal possessing placoid scales and that with cycloid scales.
Placoid scale - are found in Scoliodon
Cycloid scale - are found in Rohu.
What is the importance of pneumatic bones and air sacs in Aves?
Pneumatic bones are hollow and hence are light weight. They help to reduce the weight and hence help the birds in flight. They also provide support.