Ayesha kanwal

Trophic level Definition History types of organisms Why are pyramids important in ecology? 4 types of trophic levels

Trophic level o In ecology, the trophic level is the position that an organism occupies in a food chain what it eats, and what eats it algae → mosquito larvae → dragon fly larvae → perch

History The concept of trophic level was developed by Raymond Lindeman (1942), based on the terminology of August Thienemann (1926): "producers", "consumers" and "reducers" (modified to "decomposers" by Lindeman

Organisms get their food in one of two ways. o Autotrophs (or producers) make their own food using light or chemical energy.  Examples: plants, algae, and some bacteria. o Heterotrophs (or consumers) get organic molecules by eating other organisms or their by-products.  Examples: Animals, fungi, and many bacteria

Three types of consumers Herbivores Carnivores Omnivores

HERBIVORES Animals who eat plants such as:

CARNIVORES Animals who eat other animals such as:

OMNIVORES Animals who eat both plants and animals such as:

o Specialized heterotrophs are decomposers that break down dead organic material and wastes.

Why are pyramids important in ecology? o The classic example of a pyramid is shown here. But the pyramid structure can also represent the decrease in a measured substance from the lowest level on up. In ecology, pyramids model the use of energy from the producers through the ecosystem.

There are different trophic levels o First trophic level:  The green plants occupy first trophic level ( primary producer level)  Makes its own food  Example: Plants make food

o Second trophic level:  Plants eater (herbivores) form the second level or primary consumer level  Consumes producers  Example: Mice eat plant seeds

o Third trophic level:  Carnivores that eat the herbivores form the third level or secondary consumer level  Consumes primary consumers  Example: Snakes eat mice

o Fourth trophic level:  It is composed of tertiary consumer  Consumes secondary consumers  Example: Hawks eat snakes

o Some animals can eat plant as well as smaller animals. Therefore, they are called as Omnivores. Thus it occupies more than one level in food chain.