Morphology (biology)

The morphology (of Greek μορφή morphé, shape, form ' and λόγος lógos, word, doctrine, reason ') as part of the field of biology is the study of the structure and form of organisms. Morphological descriptions are initially related only to macroscopically visible features such as organs or tissues. With the improvement of optical instruments and various Anfärbungsmethoden appropriate investigations were already extended in the 19th century down to the cellular and subcellular level ( ultrastructural ). In the Anglo- American language is also used by "molecular morphology " spoken, so the shape description of macromolecules such as ribosomal RNA. In German-speaking countries of the morphology term is usually reserved for structures above the molecular level.

The term morphology was coined by the German anatomist of it and physiologist Karl Friedrich Burdach by Johann Wolfgang von Goethe in 1796 and independent in 1800.

Morphological disciplines

Morphological studies can be done by very different objectives, accordingly different disciplines have evolved over the history of research emerged.

A possible distinction would, for example, between comparative, functional and experimental morphology.

• The comparative morphology of trying to recognize the diversity of forms of individuals certain basic patterns or characteristics of a group of organisms and, where appropriate, to derive a classification of organisms based on characteristics.
• The aim of the functional morphology is to examine a structure with regard to a specific function. The investigation focuses on individual elements of an organism that are relevant for a particular function. A structure is therefore ( that is, the appropriateness of an organism to its life ) understood as a specialization in a particular function. The totality or the interaction of the single functions can be incorporated into a so-called Constructional description.
• In the experimental development of an organism, the morphology is mostly investigated. The ambient conditions are changed in an experiment to determine the laws of development in terms of a causal morphology ( comparison between normal and abnormal development process, causal reasoning of the observed differences ), for example.

Morphological studies can therefore be the basis of very different research directions. The purely descriptive collection of shapes and shape changes in the development opens in modern biology often in a particular classification of organisms. Thus, the morphology is the basis for the systematics and evolutionary theory (see phylogenetics ). Morphologists earlier times understood by them established classification systems are not. Than description of a stepped forth going from a common precursor Instead, was a " ideal type " or " prototype " the speech that certain groups of organisms can be assigned. In the organisms were seen in some cases also the Platonic ideas. The best-known example of such attempt is Goethe's attempt to exclude the appearance of all known plant forms an ideal-typical " archetypal plant ". This mindset is now regarded as the first step to modern evolutionary biology and is historically classified as " idealistic morphology ".

Morphology of plants

• The cormophytes consist of leaf, shoot and root axis Plant growth forms Woody plants such as trees, shrubs, dwarf shrubs and lianas.
• Herbaceous plants are plants that do not become woody.

• Foliage is the sum of the leaf organs ( leaf shape ) of deciduous trees and shrubs.
• As a node ( Node ) the area of ​​the stem axis is referred to the schedule one or more sheets. In the leaf axils are frequently formed buds from which vegetative side shoots ( axillary shoots) or inflorescences emerge.
• Phyllotaxis is the doctrine of the leaf position of plants.
• The Anisophyllie refers to the occurrence of different sheet sizes on an engine of a plant.
• Heterophyllie, also called Blattdimorphismus means training designed unequal leaves on a plant.

• Metatopie is to shift the point of attachment of the inflorescence by adhesions.

• Leaf position in mosses
• As glass hair the most colorless, hair -like elongated blade tip is referred to in some mosses.