ENERGY TRANSFER IN ECOSYSTEMS

Unit Targets:HS-LS2-3: Construct and revise an

explanation based on evidence for the cycling of matter and flow of energy in

aerobic and anaerobic conditions.

HS-LS2-4 Use mathematical representations to support claims for the

cycling of matter and flow of energy among organisms in an ecosystem.

In this unit we studied the flow of energy from the sun to producers and consumers and how nutrients cycle through an ecosystem.

Learning Target: Define a food web (Knowledge)

True or False?

A food web can best be described as the interconnected feeding relationships in an ecosystem.

True

True or False?

The original source of energy for a food web is ATP.

False: Sunlight

Energya. Is used by plants to growb. Is used by animals for daily activitiesc. Is the ability to do workd. All of the above

Answer: d

Which column of words represents abiotic factors in an environment?

A

Abiotic

Sunlight

Water

Soil

Rocks

Atmospheric gases

B

Biotic

Plants

Animals

Fungi

Bacteria

Protists

True or False?

Biotic factors in an environment are dependant on the abiotic factors?

True- For example, a human (biotic) is mostly made of water (abiotic) and uses oxygen (abiotic) for cellular respiration.

On the next slide match components of a food web with their correct description.

Primary producer Breaks down organic matter

Herbivore Meat eating

Omnivore Uses solar energy to make its own foodCarnivore Plant and meat eating

Detritivore Eats dead carcasses

Scavenger Eats organic matter

Decomposer Plant eating

Match components of a desert food web with specific examples.

Primary producer

Herbivore

Carnivore

Scavenger

Decomposer

Jack Rabbit

Bacteria

Buzzard

Cactus

Coyote

Learning Target: Interpret a food web for an ecosystem. (Reasoning)

Is this a diagram of a food chain or a food web?

Food chain- because it is a linear sequence of eating relationships.

How many trophic levels are in this food chain?

4- producer, herbivore, carnivore, decomposer

Is the snail a primary producer?

No- it is an herbivore

If the shrimp population decreases what organism will be most affected?

Sandpiper. They only eat shrimp. The mallard and egret eat other organisms.

Are there any omnivores in this food web?

Yes- The mallard is an example. It eats terrestrial plants and shrimp.

What organism not pictured would recycle the nutrients contained in the owl?

A decomposer.

What term describes the trophic level of the grasshopper?

Second level consumer

What do the arrows in a food web represent?

The direction energy flows in a food web.

Learning Target: Examine the flow of energy in an ecosystem. (skill)

Which of the following is not a type of ecological pyramid?

a.Energy pyramid

b.Food web pyramid

c.Biomass pyramid

d.Numbers pyramid

b.

Name the energy level.

1

2

3

4

How many trophic levels are shown in this pyramid?

5

What percent of energy is available to the green fish?

0.1%

How does the snail use most of its energy?

For respiration, movement and reproduction.

True or False?

90% of the energy in a trophic level is lost as heat.

True.

Summary

True or False?Most organisms depend on the sun as a source of

energy.

True

Autotrophs are the only organisms that can convert the sun’s energy to usable chemical energy in a process called photosynthesis.

True

Learning Target: Define nutrient (K)

True or False?

A nutrient is a chemical required by an organism.

True

Which column describes a nutrient and which column describes

energy?NUTRIENT

• Needed by living things for survival

• Limited supply is recycled through an ecosystem

• Examples are carbon, nitrogen and phosphorus.

ENERGY

• Needed by living things for survival

• Flows in one direction• Examples include heat

and light.

Learning Target: Examine how the non-living factors in an environment

influence what can live there. (R)

True or False?Water is a biotic factor in an environment.False- it is abioticA predator is a biotic factor in an environment.TrueBiotic factors are dependent on abiotic factors.True

Which of the following is an example of a limiting nutrient?

a.It did not rain for a week.

b.The builder removed the topsoil from the construction site.

c.My doctor said I am low on iron.

d.All of the above.

d.

Learning Target: Interpret a diagram of a nutrient cycle. (S)

1

2

34

How is carbon entering the atmosphere?-burning, decomposition, cellular respirationHow is carbon being used?-photosynthesis

What chemical is produced by the decomposition of amino acids?AmmoniumHow are nitrates used by plants and animals?To make proteins

How does a bunny obtain his daily recommended amount of phosphate?By eating plants.

Why are earthworms considered an invasive species in the nature pod?

a.They are not native

b.They are likely to harm the environment

c.They may displace native species.

d.All of the above

d.

True or False?

Invasive species may compete for nutrients with native plants.

True

Invasive species may disrupt the flow of nutrients through the food chain.

True