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Home >>Biology Dictionary >> Fibroblast - Filter Feeding
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Fecundity. The numbers of young produced by an organism during the course of its life.
Feedback inhibition. The inhibition of the first enzyme in metabolic pathway by the final product of that pathway.
Femur. Of tetrapod vertebrates, the thigh – bone. Of insects one of the segments (third from base) of the leg.
Fermentation. Decomposition of organic substances by organism, especially bacteria and yeasts.e.g. decomposition of sugar forming ethyl alcohol and carbon dioxide by yeast in making of wine, or of ethyl alcohol forming acetic acid in making of vinegar. Not usually applied to decomposition of proteins, which is called putrefaction. Sometimes means anaerobic respiration.
Fen.
A plan community on alkaline neutral or slightly acid peat that is wet and usually low lying.
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Fertilization.
The union of two special cells, the gametes, the essential process of sexual reproduction. The resulting single cell is a zygote. Fertilization has two aspects;
(a) fusion of two haploid nuclei which brings together in the zygote a selection of genes from two distinct individuals, i.e. the two parents, or from one individual in the case of self fertilization.
(b) initiation of development of a new individual.
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In parthenogenesis and psedogamy aspect
(a) occurs without aspect
(b) External fertilization, union of gametes outside body of parents, as in many aquatic animals, e.g. Echinodermata. Internal fertilization, union of the gametes inside the female, as in most terrestrial animals (insects, tetrapods) and many aquatic animals of many different phyla.
Fertilizer. A fertilizing agent added to agricultural soils, in the form of an added chemical or manure.
Feulgen reagent. A deep purple dye that stains the deoxyribose sugar of DNA in cell nuclei.
Fibre. (Bot.). Element of sclerenchyma.
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Fibroblast. (Fibrocyte). Kind of cell of irregular, branching shape, found distributed throughout vertebrate connective tissue. Function is apparently to form and maintain the extra cellular collagen and mucopolysaccharide of this tissue. Similar shaped cell occurs in many invertebrates, possibly of same function. Much used is tissue culture; only those which have not been cultured for a long time remain diploid.
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Fibrous root. A fibrous root system consists of a tuft of adventitious roots of more or less equal diameter, arising from stem base or hypocotyls, and bearing smaller lateral roots, e.g. wheat, strawberry.
Fibula. The smaller and outer of the two bones (other is tibia) in shank (below the knee) of hind-limb of tetrapod vertebrate. Lateral bone in lower leg of man.
Filicales. The order that includes the Ferns in the old classification of Pteridophytes.
Filter feeding. Feeding on minute particules strained out by a filtering organ from a current of water created by the animal. Widespread amongst aquatic animals, e.g. Lamellibranchia, Brachiopoda, many Crustacea, Ascidia.
Fimbriate.
(Of plant structures ) having a fringe on the margin.
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Fins. The locomotory organs of aquatic vertebrates. In fish there are typically one or more dorsal and ventral fins (sometime continuous), whose function is balance; a caudal fin around the tail, which is the main propulsive organ; and two paired fins; the pectoral fins attached to the pectoral (shoulder) girdle and the pelvic fins attached to the pelvic (hip) girdle, which are used in steering. These paired fins are homologous with the limbs of tetrapods. Fins are strengthened by a number of flexible fin rays, which may be cartilaginous, bony and jointed, horny, or fibrous and jointed.
Fin rays. The skeletal structures that give rise to shape of fins in fish. They may be cartilaginous, bony or fibrous.
Firit-order reaction. A reaction in which the rate of reaction is directly proportional to the concentration of one of the reactants, either product or substrate.
Fission. A process of asexual reproduction by the sub-division of the parent body into two or more parts which are approximately equal and become independent individuals. Commonest form of reproduction in protozoans. It can be binary fission of the transverse type (e.g. Amoeba, Paramecium) or longitudinal type (e.g. Euglena. Trypanosoma) or multiple fission (Plasmodium, Amoeba).
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