15.3 Nutritional Relationships in an Ecosystem

• Biology
• Secondary Education

PRODUCERS AND CONSUMERS

PSALM 104: 10 - 14

He makes springs pour water into the ravines;

    it flows between the mountains.

They give water to all the beasts of the field;

    the wild donkeys quench their thirst.

The birds of the sky nest by the waters;

    they sing among the branches.

He waters the mountains from his upper chambers;

    the land is satisfied by the fruit of his work.

He makes grass grow for the cattle,

    and plants for people to cultivate—

    bringing forth food from the earth: 

01:06

What do producers do?

02:00

What do consumers do?

03:04

What do decomposers do?

Organisms that make their own food using inorganic (nonliving) energy source are called AUTOTROPS or PRODUCERS.

2 types of autrophs

PHOTOAUTOTROPHS

CHEMOAUTOTROPHS

PHOTOAUTOTROPHS

- green plants

- algae

- cyanobacteria

obtain energy from sunlight

CHEMOAUTOTROPHS

obtain energy from chemical substances rather than from sunlight

Sulfur and nitrogen are used by some bacteria to get energy.

HETEROTOPHS or CONSUMERS

Cannot produce their own food and must obtain energy from sources (living things), usually by eating organisms

HERVIBORES & CARNIVORES

HERBIVORES

are consumers that

 feed on plants

CARNIVORES

are consumers that feed on other animals

SCAVENGERS

Carnivores that do not kill their own food but feed on dead animals instead

OMNIVORES

Consumers that feed on both plants and animals

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DECOMPOSERS

bacteria and fungi that feed on detritus by secreting enzymes that break it down into simpler molecules.

producer

1. human being
2. green plants

consumer

1. algae
2. deer

herbivores

1. parrot, koala, butterfly
2. tiger, penguin, wolf

carnivores

1. cow, camel, beaver
2. lions, hawks, snakes

Write one omnivore...

detritivores

1. crabs, earthworms, ants
2. fungi, bacteria

The different feeding positions in a food chain or web are called TROPHIC LEVELS.

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Living things are classified into trophic levels by their position in the food chain.

A FOOD WEB consists of several interconnected food chains involving many different species.

It is a classification that describes its feeding relationship to other organisms in its ecosystem.

They represent the first trophic level.

They represent the second trophic level.

They represent the third trophic level.

They are the fourth trophic level.

It is a model used by ecologists to show the nutritional relationships among organisms in an ecosystem.

Living things are classified into trophic levels by their position in a food chain.

YES

NO

Who designed food chains and what was the purpose?

God had a plan when he created the earth.

Everything in nature tells us he had a design and took care of every single detail.