| TERM | GROUP | DEFINITION | |
|---|---|---|---|
| WATER VASCULAR SYSTEM | NP | ANIMALS | Pronunciation: Etymology: The water vascular system is a series of internal tubes through which water circulates and provides hydraulic force for movement. The water vascular system connects to the outside by a pore called a madreporite. |
| WEIGHTED CHARACTER | NP | SYSTEMATICS | Pronunciation: Weighted is a common English word. Etymology: Weight comes from the Old English word, wegan, which means to find the weight. A weighted character refers to the condition when particular characters are considered more important (that is less likely to change). For example, a developmental character might be much less likely to occur and still produce a viable organism than a structural character. MacClade can weight to characters from 1 to 9. |
| WHIPLASH FLAGELLUM (WHIPLASH FLAGELLA) | N | ANIMALS, PLANTS, PROTISTS, FUNGI | Pronunciation: Etymology: (1) A whiplash flagellum is a eukaryotic 9+2 flagellum with few or no flagellar hairs or scales. These may be directed anteriorly or posteriorly. (2) A whiplash flagellum is free of hair-like mastigonemes and usually is trailing or posteriorly-directed. |
| WHORLED LEAVES | NP | PLANTS | Pronunciation: Etymology: When plants have more than two leaves per node, they are said to have whorled leaves. |
| WING | N | ANIMALS | Pronunciation: Etymology: Modified epidermal extentions of insects and modified forelimbs in vertebrates (pterodactyls, bats, and birds). |
