Any definite part of a plant structure (e.g. a cell, a leaf).
Any member of a plant—as a petal, stamen, leaf, branch, etc.
A part of the body consisting of two or more tissues organized to perform a specific function.
A part of the body which is distinct from other parts and has a particular function, e.g. the liver, an eye or ovaries.
Part of the body that forms a structural unit concerned with a specific function; it often consists of more than one kind of tissue. An example is the lungs, organs that are responsible for the exchange of carbon dioxide and oxygen.
A body part composed of more than one tissue that performs a specific function or functions. The specific function of an organ, such as the heart, lungs, and liver, is essential to the functioning of the whole body. In animals, organs are usually made up of several tissues, one of which generally predominates and determines the chief function of the organ.
A part of the body, composed of more than one tissue, that forms a structural unit responsible for a particular function (or functions). Examples are the heart, lungs, and liver.
A collection of different tissues that form a distinct structure in the body with a particular function or functions. The liver, for example, comprises a collection of different metabolic cells bound together with connective tissue and liberally supplied with blood vessels; it performs vital functions in the breakdown of substances absorbed from the gastrointestinal tract. Other examples of organs are the kidneys, brain and heart.
A body structure made of several tissues that all contribute to specific functions. Many organs occur in pairs. In such pairs, one organ may be extirpated and the remaining one can perform all necessary functions peculiar to it. One third to two fifths of some organs may be removed without loss of function necessary to support life.
Structures composed of specialized tissues designed to perform specific functions in plants and animals.
A part of the body that performs a specific function. For example, the heart is an organ.
An amalgamation of diverse tissues fused into a well-defined structural entity for the purpose of carrying out particular functions. For instance, the brain is composed of nerve tissue and supportive tissue intricately arranged to receive, process, and transmit information.
A structurally organized and recognizable part of the body, comprising a collection of closely related tissues, all working together to carry out a particular function or functions, such as the role of the stomach in the process of digestion.