Mention one example each for aniamls with chitinous exoskeleton and those covered by a calcareous shell.

Explanation

Every living form maintain a proper shape, size and structure. In multicellular lower organisms the shape of body is maintained by certain biological materils like chitin and calcium substances. Chitinous exoskeleton is the characterietic feature of arthropods (e.g., cockroach, termite, wasp) whereas, calcareous shell is present in molluscs (gastropods). (e.g., snail and slugs).