BioScience Dictionary

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Found Organisms 312 times.

Displaying results 1 to 10.

1. Abiogenesis
Early theory that held that some organisms originated from nonliving material.

2. Abiogenic
Abiogenic refers to things not involved with or produced by living organisms.

3. Absolute filter
A fine-pored, steam-sterilizable filter that is used to trap airborne microorganisms. The filter's pores are about 2 micrometers in diameter, smaller than the particles it is designed to remove.

4. Acanthocephala (spiny-headed worms)
A phylum of parasitic organisms, from one of three general classes, generally referred to as spiny-headed worms. They are notable for their lack of a digestive tract.

5. Accessory flower parts
Sepal and petal organs found on flowers. The sepals and petals are not essential for pollination but may aid in attracting insects or other organisms.

6. Acetyl reduction assay (acetylene reduction assay)
A technique for measuring the nitrogen fixation activity in photosynthetic organisms. It uses a flame ionization detector and a gas chromatography apparatus to determine the reduction of acetylene to ethylene by the enzyme nitrogenase .

7. Activated sludge process
A method of treating sewage and wastewater through microbial oxidation. Sewage previously treated in settling tanks is aerated to encourage the growth of nonpathogenic aerobic microorganisms ( bacteria , yeast s, molds and protozoans) which break the organic matter down into carbon dioxide, water, and simple salts. After this activated sludge is produced, the wastewater undergoes further processing through anaerobic digestion, filtering, and chlorination.

8. Adaptation
Tendency of an organism to suit its environment; one of the major points of Charles Darwin's theory of evolution by natural selection : organisms adapt to their environment. Those organisms best adapted will have a greater chance of surviving and passing their genes on to the next generation.

9. 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 .

10. Ambulatory
An organism which is able to move from place to place, and is not stationary. Most often the term is used to describe organisms which can walk.

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