Chapter 25.3, Problem 1NV

Summary Introduction

To define:

The term mantle, radula, gills, open circulatory system, closed circulatory system, nephridia, and siphon.

Explanation of Solution

Mantle is an outermost covering of internal organs of molluscs. It plays an important role in molluscs and attachment of the internal body to external shell.

Radula is an organ in molluscs that is used by them to scraping food of the rocks.

Gills are the part of respiratory system of some aquatic animals and help in delivery of oxygen and removal of carbon dioxide.

Open circulatory system is a type of respiratory system, in which the blood and the body fluid surrounding the tissues are in direct contact.

Closed circulatory system represents isolated circulatory circuit in some animals, where the blood flows in flood vessels and mixing of the blood with interstitial fluid does not takes place.

Nephridia are tubules that are involved in the excretion of nitrogenous wastes and osmoregulation.

Siphon is a tube which is part of mollusc’s mantle and help in exchanging fluid from the external atmosphere.