These are called valves- some molluscs have two and are called BIVALVES, whilst others have three and are called TRIVALVES. The latter are held to be higher up the evolutionary scale. The bivalves are the clams, mussels, oysters and scallops. The adults all have two hinged shells (valves). Some of these animals circulate water carrying the microorganisms that they eat and oxygen for respiration through tubes called "siphons" that they can extend from between the shells on the anterior end so they can stay safely hidden in the mud or sand.
A scientist who studies mollusks is called a malacologist.
Univalves
worms mollusks
Water and minerals are absorbed by the plant's roots and transported upward through specialized tubes called xylem. This process is driven by transpiration, where water evaporates from the leaves, creating tension that pulls water from the roots. The movement of water and minerals through the plant body is essential for nutrient uptake and maintaining plant structure.
Bronchial Tubes
Irrigation.
No. Aqueducts are water transportation systems--you could call them large water pipes. They were/are used to bring water where it is needed.
non vascular
The bronchioles
tha answer is vascular plants
bronchioles
tha answer is vascular plants