produced by Photosynthesis of a plant equals the oxygen 

 absorbed in Respiration. 



Compensation Level (Point) 



The depth in a body of water at which the Compensation 

 intensity of a given plant occurs. 



Competition 



The condition that exists when the requirements of one 

 or more of the organisms living in a community cannot be 

 obtained from the available supply of resources, cf. Exploita- 

 tion, Interference. 



Competitive Exclusion Principle 



A generalization "that states that as a result of competition 

 two similar species rarely if ever occupy the same ecological 

 Niche. Also termed Cause's principle, Grinnell's axiom. 



Competitor 



An organism competing with one or more other organ- 

 isms. 



Complementary Genes 



Two or more genes that by their joint action produce a 

 character. 



Complete Flower 



A flower that has all of the usual parts; sepals, petals, 

 stamens, and one or more pistils. 



Complex 



See Community complex. 



Complex Gradient 



A gradient comprising a mixture or a combination of 

 environmental conditions, cf. Ecocline. 



Composite 



A plant in the family Compositae, e.g., aster, sunflower. 



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