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    malformation
    /ˌmalfɔːˈmeɪʃn/

    noun

    • 1. an abnormally formed part of the body: "the drug may cause malformations in the developing embryo"

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  3. the condition of being wrongly formed, or a part of something, such as part of the body, that is wrongly formed: Exposure to radiation can lead to malformation of the embryo. She was born critically ill with a severe malformation of the heart.

  4. The meaning of MALFORMATION is irregular, anomalous, abnormal, or faulty formation or structure. How to use malformation in a sentence.

  5. Malformation definition: faulty or anomalous formation or structure, especially in a living body. See examples of MALFORMATION used in a sentence.

    • Overview
    • Plant malformations
    • Exaggerated growth
    • Alteration of floral parts
    • Translocation of organs

    malformation, in biology, irregular or abnormal structural development. Malformations occur in both plants and animals and have a number of causes.

    The processes of development are regulated in such a way that few malformed organisms are found. Those that do appear may, when properly studied, shed light on normal development. The science of teratology—a branch of morphology or embryology—is concerned with the study of these structural deviations from the normal, whether in animals or plants.

    Monstrosities, freaks, and other malformations have interested botanists for many years. There are numerous categories of such growth abnormalities in plants, and these are often related only loosely or not at all to one another.

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    Sometimes divergence from the normal represents merely a quantitative change, which is evidenced by a harmonious but exaggerated manifestation of the normal developmental processes. This is well illustrated in the so-called bakanae, or foolish seedling disease, of rice. The bakanae disease is caused by the fungus Gibberella fujikuroi. Diseased plants are often conspicuous in a field because of their extreme height and pale, spindly appearance. This exaggerated growth response was found to be due to specific substances, known as gibberellins, which were produced by the fungus. Evidence is now available to indicate that gibberellins, also produced by higher plant species, participate directly as an essential growth-regulating system in all higher plant species. The gibberellins of either fungal or higher plant origin stimulate the normal development of certain genetic dwarfs of maize and peas, which cannot themselves produce the gibberellins in amounts sufficient for their normal development.

    A common deformity of tobacco, called frenching, occurs in most tobacco-growing regions of the world. The advanced state of this condition is characterized by a cessation of terminal bud and stem growth. When dominance of the stem tips is lost, the buds in the axils of the leaves develop, and unusually large numbers of leaves (as many as 300) appear on a plant. The leaves are characteristically sword- or string-shaped because of the failure of the leaf blades to develop. Such plants have the appearance of a rosette. Although the cause of frenching has not yet been unequivocally established, it is thought to be due to a toxic substance produced by the nonpathogenic soil bacterium Bacillus cereus.

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    Under the stimulus of pathogenic organisms of the most diverse kinds, the sepals, petals, stamens, or pistils of a flower may be transformed into structures that are very different in appearance from those found normally. Certain viruses can cause enlargement of the leaflike flower parts (sepals) surrounding the base of a blossom in plants of the n...

    Plant organs may arise in unusual places as a result of the infection by certain types of pathogenic agents. The carrot-yellows virus, for example, stimulates production of aerial tubers in the axils of the leaves of potato plants. Large numbers of adventitious roots (arising in abnormal places) appear on the stems of tomato plants infected with the bacteria Pseudomonas solanacearum and Agrobacterium tumefaciens as well as the Fusarium wilt fungus and the cranberry false blossom virus.

    An extreme example of adventitious shoot formation is found in Begonia phyllomaniaca after shock. In this instance, small plantlets develop spontaneously in incredible numbers from the superficial cell layers of the leaf blades, petioles, and stems. The adventitious shoots do not arise from preformed buds but develop from cells at the base of hairs and especially from certain glands present in great numbers in young stems and leaves of this species. Although these plantlets develop a vascular system of their own, the vast majority never succeed in connecting that system with the vascular system of the host. They must therefore be regarded not as branches but rather as independent organisms.

  6. A malformation in a person's body is a part which does not have the proper shape or form, especially when it has been like this since birth.

  7. Definition of malformation noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

  8. malformation. (ˌmælfɔːˈmeɪʃən) n. 1. the condition of being faulty or abnormal in form or shape. 2. (Pathology) pathol a deformity in the shape or structure of a part, esp when congenital. malˈformed adj.

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