Energy Flow and Trophic Levels in Ecosystems

These flashcards cover key concepts related to energy flow, trophic levels, and ecological interactions, as discussed in the lecture.

What are autotrophs and their significance in a community?

Autotrophs are self-feeding organisms like plants, protists, and cyanobacteria that produce carbohydrate energy through photosynthesis; they form the base of the food chain.

What percentage of carbohydrate energy comes from photosynthesis?

99% of all carbohydrate energy comes from photosynthesis.

What is the difference between autotrophs and heterotrophs?

Autotrophs produce their own energy, while heterotrophs must consume other organisms for energy.

What is the role of decomposers in an ecosystem?

Decomposers recycle nutrients by consuming dead organisms and waste, returning inorganic materials to the soil.

What happens to energy as it moves up trophic levels?

Energy decreases by about 90% on average with each trophic level due to losses to metabolism and heat.

What is biomagnification?

The process by which toxins increase in concentration as they move up the food chain.

Why do herbivores have a tough life?

Herbivores primarily consume plant material that is mostly cellulose, which is difficult to digest and provides low nutritional value.

What are the two main types of carnivores?

Primary carnivores (first-level) feed exclusively on herbivores, while secondary carnivores (higher-level) feed on other carnivores.

What is a food web?

A food web is a complex diagram that shows all the feeding relationships and interactions in an ecosystem.

How do heavy metals enter ecosystems?

Heavy metals enter ecosystems primarily through mining activities and emissions from coal-burning power plants.