Ecosystems Introduction

Introduction to Ecosystem

Multiple Choice

"As a student looked out the window, the student observed koi fish swimming in a pond. There were lilly pads floating in the water and purple flowers leaning gently over a bed of rocks."

This image and narrative describe a(n)

• ecosystem

• food web

• habitat

• food chain

The ecosystem is the structural and functional unit of ecology where the living organisms interact with each other and the surrounding environment. In other words, an ecosystem is a chain of interactions between organisms and their environment.

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​Ecosystem

Multiple Choice

What is an ecosystem?

• A community of non-interacting organisms and their physical environment.

• A biological community of interacting organisms and their chemical environment.

• A biological community of interacting organisms and their physical environment.

• A community of non-interacting organisms and their chemical environment.

Multiple Choice

Which of the following would be considered an ecosystem?

• a rock

• an owl and a mouse

• tropical rainforest

• fungus

Multiple Choice

Do ecosystems have a particular size?

• 1 square mile

• 10 square miles

• 100 square miles

• none of the above, ecosystems do NOT have one size.

• It regulates the essential ecological processes, supports life systems and renders stability.

• It is also responsible for the cycling of nutrients between biotic and abiotic components.

• It maintains a balance among the various trophic levels in the ecosystem.

• It cycles the minerals through the biosphere.

• The abiotic components help in the synthesis of organic components that involves the exchange of energy.

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Function of Ecosystem:

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Multiple Choice

Function of Ecosystem, except....

• It regulates the essential ecological processes, supports life systems and renders stability.

• It maintains a balance among the various trophic levels in the ecosystem.

• It is also responsible for the cycling of nutrients between biotic and abiotic components.

• It is also responsible for the cycling of energy between biotic and abiotic components.

• Energy flow – It is the sequential process through which energy flows from one trophic level to another.

• Decomposition – It is the process of breakdown of dead organic material.

• Nutrient cycling – In an ecosystem nutrients are consumed and recycled back in various forms for the utilisation by various organisms.

Functional units of an ecosystem or functional components that work together in an ecosystem are:

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Multiple Choice

Functional units of an ecosystem or functional components that work together in an ecosystem are, except...

• Energy flow

• Decomposition

• Nutrient cycling

• Photosynthesis

• There are two types of ecosystem:

  • Terrestrial Ecosystem

  • Aquatic Ecosystem

Type of Ecosystem:

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Multiple Choice

The desert is a ___________.

• Terrestrial Ecosystem

• Aquatic Ecosystem

Multiple Choice

What biotic factors are likely to be present in a river ecosystem?

• coral, clownfish, sponges

• water, soil, starfish

• otters, ducks, bass

• water, soil, air, sunlight

Structure of Ecosystem:

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Structure of Ecosystem:

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• The structure of an ecosystem is characterised by the organisation of both biotic and abiotic components. This includes the distribution of energy in our environment.

• The biotic and abiotic components are interrelated in an ecosystem. It is an open system where the energy and components can flow throughout the boundaries.

Abiotic Components

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Abiotic components are the non-living component of an ecosystem.  It includes air, water, soil, minerals, sunlight, temperature, nutrients, wind, altitude, turbidity

Multiple Choice

What is an abiotic factor?

• A living condition or thing, that influences or affects an ecosystem and the organisms in it.

• A non-living condition or thing, that does not affect an ecosystem and the organisms in it.

• A non-living condition or thing, that influences or affects an ecosystem and the organisms in it.

• A living condition or thing, that does not affect an ecosystem and the organisms in it.

Biotic Components

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Biotic components refer to all life in an ecosystem.  Based on nutrition, biotic components can be categorised into autotrophs, heterotrophs and saprotrophs (or decomposers).

Multiple Choice

What is a biotic factor?

• Any non-living component that affects the population of another organism, or the environment.

• Any living component that has a population.

• Any living component that affects the population of another country.

• Any living component that affects the population of another organism, or the environment.

Producers

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Producers include all autotrophs such as plants. They are called autotrophs as they can produce food through the process of photosynthesis. Consequently, all other organisms higher up on the food chain rely on producers for food.

Consumers

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Consumers or heterotrophs are organisms that depend on other organisms for food. Consumers are further classified into primary consumers, secondary consumers and tertiary consumers.

Multiple Choice

What type of organism makes its own food?

• consumer
• carnivore
• producer
• animal

Multiple Choice

What are organisms that use other organisms for food in order to gain energy?

• decomposers
• producers
• herbivores
• consumers

Multiple Choice

Which are examples of consumers?

• grass and cows
• turtles and seaweed
• owls and bears
• sun and mushrooms

Multiple Choice

You see a grasshopper on a leaf. What could you say about how the grasshopper gets its energy?

• It gets energy from the air.
• It gets energy from the leaf.
• It gets energy from soil.
• It gets energy from water.

Consumers

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• Primary consumers are always herbivores that they rely on producers for food.

• Secondary consumers depend on primary consumers for energy. They can either be a carnivore or an omnivore.

• Tertiary consumers are organisms that depend on secondary consumers for food.  Tertiary consumers can also be an omnivore.

• Quaternary consumers are present in some food chains. These organisms prey on tertiary consumers for energy. Furthermore, they are usually at the top of a food chain as they have no natural predators.

Consumers - Detritivore

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• Detritivores are organisms that feed on the organic waste of dead plants and animals

• Detritivore breaks down detritus into smaller particles. This process is called fragmentation.

Consumers - Detritivore

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• Decomposers include saprophytes such as fungi and bacteria. They directly thrive on the dead and decaying organic matter.  Decomposers are essential for the ecosystem as they help in recycling nutrients to be reused by plants.

• Decomposers secrete digestive enzymes that breakdown dead and waste materials into simple, inorganic materials, which are subsequently absorbed by them.