Ecosystem and Food Chain Basics

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Questions and Answers

What is the main purpose of a food chain in an ecosystem?

To show the evolution of organisms over time

To represent the feeding interactions between organisms (correct)

To identify the habitat of a specific species

To track the migration patterns of organisms

In the freshwater lake ecosystem example, what is the energy source for the aquatic plants?

The energy from the osprey

The energy from the stonefly larva

The energy from the sun through photosynthesis (correct)

The energy from the fish

What is transferred from one organism to another in a food chain?

Energy (correct)

Carbon dioxide

Oxygen

Water

What is true about the organisms in a food chain?

Some organisms are producers, and some are consumers Signup and view all the answers

What can be said about the energy flow in an ecosystem?

Energy is transferred from one organism to another in an ecosystem Signup and view all the answers

What is the direction of energy flow in a food chain?

From one trophic level to the next Signup and view all the answers

What is the role of autotrophs in an ecosystem?

They produce their own food through photosynthesis or chemosynthesis Signup and view all the answers

What is the typical diet of a tertiary consumer?

Secondary consumers Signup and view all the answers

What is the purpose of trophic levels in an ecosystem?

To show the flow of energy from one organism to another Signup and view all the answers

What is the term for an organism that feeds on both plants and meat?

Omnivore Signup and view all the answers

What is the main purpose of a food web?

To represent all of the food chains within an ecosystem and show how feeding relationships are interconnected Signup and view all the answers

In which direction does energy flow through an ecosystem according to the food web?

From lowest trophic levels to highest trophic levels Signup and view all the answers

What percentage of energy is typically transferred from one trophic level to the next?

10% Signup and view all the answers

Why is energy not transferred perfectly from one trophic level to the next?

Because some energy is lost due to heat, metabolism, and matter not consumed Signup and view all the answers

What happens to the remaining 90% of energy in the example of the grasshopper and the robin?

It is lost due to heat, metabolism, or matter not consumed Signup and view all the answers

Study Notes

Ecosystem and Food Chain

An ecosystem is the complex whole of organisms living in an area, along with their interactions.
Interactions between organisms include feeding to obtain energy, which is represented by a food chain.
A food chain shows the feeding interactions in an ecosystem, depicting who eats whom and the flow of energy.

Food Chain Examples

Terrestrial food chain: grass -> plant-eating insects -> meat-eating insects -> frog -> snake -> bird of prey
Marine food chain: algae -> plankton -> crustaceans -> fish -> dolphin -> shark

Energy Flow in an Ecosystem

Energy cannot be created or destroyed, but is transferred from organism to organism within an ecosystem through feeding.
Energy flows from producers to consumers, in one direction, as each organism eats the one below it on the chain.

Trophic Levels

Trophic levels describe the levels of energy flow in the food chain, classifying where an organism falls within an ecosystem.
Energy flows from producers (lowest trophic level) to quaternary consumers (highest trophic level).
The trophic levels can be visualized as a pyramid, with producers at the base and quaternary consumers at the top.

Trophic Level Classification

Producers (autotrophs): create their own food through photosynthesis or chemosynthesis.
Primary consumers: feed on producers, exclusively herbivores.
Secondary consumers: feed on primary consumers, can be carnivores or omnivores.
Tertiary consumers: feed on secondary consumers, typically predators, can be carnivores or omnivores.
Quaternary consumers: apex predators, feed on tertiary consumers and below, typically carnivores but can be omnivores.

Herbivores, Carnivores, and Omnivores

Herbivores: feed exclusively on plant matter, primary consumers.
Carnivores: feed exclusively on meat, can feed at secondary consumer trophic level or above.
Omnivores: feed on both plants and meat, can feed at all trophic levels from primary to quaternary consumers.

Food Web

A food web represents all of the food chains within an ecosystem and shows how feeding relationships between organisms are interconnected.
Energy flows in an upward trend from the lowest trophic level of producers to the highest trophic levels of quaternary consumers.
Energy can flow between organisms in different food chains, as shown by the food web.

Energy Flow in a Food Web

Energy is not transferred perfectly from one trophic level to the next, with a 10% rule of thumb for energy transfer.
The remaining 90% of energy may be lost due to heat, metabolism, or matter not consumed.
This energy flow pattern is not limited to a single food chain, but occurs throughout the entire ecosystem.

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Description

Learn about the complex relationships between organisms in an ecosystem, including feeding interactions and energy exchange. Understand how food chains represent these interactions in ecosystems like freshwater lakes.