AP BIOLOGY

Detailed explanation-1: -A famous example of the competitive exclusion principle is shown in the figure below, which features two types of single-celled microorganisms, Paramecium aurelia and Paramecium caudatum. When grown individually in the lab, both species thrive.

Detailed explanation-2: -Competition describes the situation when two species use the same limited resource and fight with each other for the resource to survive. The classical example of competition is the laboratory experiment between Paramecium caudatum and Paramecium aurelia (Gause 1934).

Detailed explanation-3: -Example 1 of the competitive exclusion principle or Gause’s principle: two spp. of Paramecium. Gause (1934) placed two species of Paramecium into flasks containing a bacterial culture that served as food. Thus, in this artificial laboratory system both species of paramecium were forced to have the same niche.

Detailed explanation-4: -Two species of Paramecia, Paramecium aurelia and Paramecium caudatum were grown in a single flask where bacteria were used as the food source.

Detailed explanation-5: -When grown individually in the laboratory, they both thrive. But when they are placed together in the same test tube (habitat), P. aurelia outcompetes P. caudatum for food, leading to the latter’s eventual extinction.