BioScience Dictionary

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Found Species 296 times.

Displaying results 1 to 10.

1. Acid-fast stain
A staining technique used to determine the cell wall property of a microorganism. After stained with dye such as hot carbol fuschin, an acid-fast organism, (.e.g. Mycobacterium species) will retain the color in its cell wall after being washed with acid-alcohol.

2. Adaptation
The condition of showing fitness for a particular environment, as applied to characteristics of a structure, function or entire organism; a modification of a species that makes it more fit for reproduction and/or existence under the conditions of its environment.

3. Adaptive radiation
The evolution of new species or sub-species to fill unoccupied ecological niches.

4. Adaptive radiation
The development of a variety of species from a single ancestral form; occurs when a new habitat becomes available to a population . Evolutionary pattern of divergence of a great many taxa from a common ancestral species as a result of novel adaptations or a recent mass extinction . Examples: mammals during the Cenozoic Era after the extinction of dinosaurs at the close of the Mesozoic Era flowering plants during the Cretaceous Period diversified because of their reproductive advantages over gymnosperm and non-seed plants that dominated the floras of the world at that time.

5. Agar
This gelatinous material, an extract from red algae (mainly Gelidium and Gracilaria species), is most frequently used as a culture medium, especially for bacteria. It is also used as a thickener in foods, but humans can't digest it.

6. Age-class
A group of individuals of a species that have the same age.

7. Agglutination
* The clumping together of cells due to the binding of agglutinin (a protein) molecules on each cell's surface. * The clumping together of two organisms of the same species for the purpose of sexual reproduction. Often conducted by means of a carbohydrate on one organism and a protein on the other, resulting in a glycoprotein .

8. Agonistic animal behavior
Aggressive behaviors among animals, which may be within a species or between two different species, and may be a form of territoriality, dominance or mating strategy.

9. Algae
This is a large group of diverse unicellular and multicellular aquatic plants; they grow in both fresh water and seawater and are used commercially as a source of thickeners ( agar , agarose , algin , carrageenan ) and pigments such as beta carotene . Some countries harvest them as food; Spirulina is produced by Israel and Mexico, and the Japanese consume some species of Chlorella. Some species of algae are important commercial pests because they clog pipes and foul pools and reservoirs.

10. Algin (alginate)
This gelatinous material, a polysaccharide extract from brown algae , is widely used in foods, medicines, and industrial and household products. The main algae that produce it are Laminaria species and Macrocystis pyrifera (a chemically different version of algin is produced by the bacterium Azobacter vinelandii.)

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