Mention the functions of following words
a) Air bladder b) flame cells
e) Water vascular system
c) Radula
d) Nephridia
Answers
a) Swim bladder, also called air bladder, buoyancy organ possessed by most bony fish. ... It contains gas (usually oxygen) and functions as a hydrostatic, or ballast, organ, enabling the fish to maintain its depth without floating upward or sinking. It also serves as a resonating chamber to produce or receive sound.
b) A flame cell is a specialized excretory cell found in the simplest freshwater invertebrates, including flatworms, rotifers and nemerteans; these are the simplest animals to have a dedicated excretory system. ... The function of these cells is to regulate the osmotic pressure of the worm, and maintain its ionic balance.
c) The water vascular system is a hydraulic system used by echinoderms, such as sea stars and sea urchins, for locomotion, food and waste transportation, and respiration. The system is composed of canals connecting numerous tube feet.
d) The radula, part of the odontophore, may be protruded, and it is used in drilling holes in prey or in rasping food particles from a surface. It is supported by a cartilage-like mass (the odontophore) and is covered with rows of many small teeth (denticles).
e) Nephridium, unit of the excretory system in many primitive invertebrates and also in the amphioxus; it expels wastes from the body cavity to the (usually aquatic) exterior.