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.
Name the animal, which exhibits the phenomenon of bioluminescence. Mention the phylum to which it belongs.
What is the importance of pneumatic bones and air sacs in Aves?
Which group of chordates possess sucking and circular mouth without jaws?
What is the role of radula in molluscs?
