Ecosystems revision

Ecosystems & Distribution of Organisms

Revision Lesson

Ecosystem Terms

You should be able to give the meaning of the following terms

Species, biodiversity, population
producer, consumer, herbivore
carnivore, omnivore, predator
prey, community, habitat.

Learning Intentions and Success Criteria

Learning Intention:
To learn about the factors which affect the distribution of organisms.
Success Criteria:


By the end of the lesson, I can:

• State the definition of biotic and abiotic factors.

• Identify and give examples of biotic and abiotic factors.

Multiple Choice

A group of organisms of the same species

• Community

• Population

• Niche

• Biodiversity

Multiple Choice

Where an organism lives

• Habitat

• Ecosystem

• Biome

• Niche

Multiple Choice

All the organisms in one area

• Niche

• Species

• Population

• Community

Multiple Choice

All the living organisms and non living factors they interact with

• Habitat

• Community

• Ecosystem

• Population

Multiple Choice

An organism that makes its own food using energy from the sun

• Consumer

• Producer

• Herbivore

• Carnivore

Multiple Choice

A group of organisms that can interbreed to produce fertile offspring

• Population

• Community

• Niche

• Species

Learning Intentions and Success Criteria

Learning Intention:
To learn about niches of organisms and competition.
Success Criteria:
By the end of the lesson, I can:

• State the definition of a niche.

• Describe the niche of an organism.

• State the definition of intraspecific and interspecific competition.

• Identify examples of intraspecific and interspecific competition.

Multiple Choice

The role of an organisms in its ecosystem

• Population

• Community

• Niche

• Species

Competition

• Competition is when two or more organisms require the same or

similar resources which are in short supply.

Competition in

plants

Nutrients

Light

Water

Space

Competition in

animals

Water

Food

Habitat

Mates

Types of Competition

Competition exists between members of the same species.

It also exists between species!

We give names to describe these types of competition.

Interspecific Competition

• Interspecific competition between individuals of different species for

similar resources.

• For example: red and grey squirrels.

Interspecific

=

Different

Intraspecific Competition

• Intraspecific competition occurs between members of the same

species for the same resources.

• It is more intensive than interspecific as the individuals have the same

niche.

Intraspecific

=

Same

Multiple Choice

Which of the following rows correctly describes a type of competition?

• A

• B

• C

• D

Learning Intentions and Success Criteria

Learning Intention:

To learn about biotic and abiotic factors
Success Criteria:

By the end of the lesson, I can:

• State the definition of biotic factors

• Give examples of biotic factors

• State the definition of abiotic factors

• Give examples of abiotic factors

Competition for

resources

Living factors of the
environment

Grazing

Predation

Food availability

Disease

Biotic Factors

Light Intensity

Abiotic Factors

Temperature

pH

Moisture

Non-living factors of the
environment

​

Multiple Choice

Is the factor is biotic or abiotic?

Temperature

• Abiotic

• Biotic

Multiple Choice

Is the factor is biotic or abiotic?

Disease

• Abiotic

• Biotic

Multiple Choice

Is the factor is biotic or abiotic?

pH

• Abiotic

• Biotic

Multiple Choice

Is the factor is biotic or abiotic?

Competition

• Abiotic

• Biotic

Multiple Choice

Is the factor is biotic or abiotic?

Soil moisture

• Abiotic

• Biotic

Multiple Choice

Is the factor is biotic or abiotic?

Food availability

• Abiotic

• Biotic

Multiple Choice

Is the factor is biotic or abiotic?

Humidity

• Abiotic

• Biotic

Multiple Choice

Is the factor is biotic or abiotic?

Wind speed

• Abiotic

• Biotic

Multiple Choice

Which of the following statements is true of predation?

• It is an abiotic factor and causes a decrease in prey numbers

• It is an abiotic factor and causes an increase in prey numbers

• It is a biotic factor and causes a decrease in prey numbers

• It is a biotic factor and causes an icrease in prey numbers

Multiple Choice

Is the factor is biotic or abiotic?

Predation

• Abiotic

• Biotic

Multiple Choice

An ecosystem consists of abiotic factors plus a

• community and its biodiversity

• population and its biodiversity

• population and its habitat

• community and its habitat

Multiple Choice

Which line in the table correctly identifies biotic and abiotic factors that can affect a population?

• A

• B

• C

• D

Open Ended

Soil moisture and temperature are abiotic factors that can affect plant growth.

Name one other abiotic factor that can affect pant growth.

Learning Intentions and Success Criteria

Learning Intention:
To learn about how to measure abiotic factors

Success Criteria:

By the end of the lesson, I can:

• Describe how to measure light intensity and identify sources of error.
• Describe how to measure soil moisture and identify sources of error.
• Describe how to measure temperature and identify sources of error.
• Describe how to measure pH and identify sources of error.

Light Intensity – Light Meters

• At soil level, point the light

sensitive panel towards
direction of maximum light
intensity.

• Measure using the meter.

Light sensitive

panel

Soil Moisture/pH Meter

• Insert the probe into the soil,

allow meter to settle.

• Measure using the meter.

Moisture probe

Measuring Abiotic Factors

Abiotic factor

Equipment used for

measurement

Possible source of error

Ways to minimise error

Light intensity

Light meter

1.

Observer casts shadow on
meter.

2.

Taking measurements at
different time of day.

1.

Do not cast shadow over
light sensitive panel.

2.

All measurements taken as
near the same time of day
as possible.

Soil Moisture

Moisture meter

1.

Moisture remains on the
probe

1.

Wipe probe after each
measurement

pH

pH meter

1.

Moisture remains on the
probe

1.

Wipe probe after each
measurement

Temperature

Thermometer

1.

Taking measurement before
meter has settled.

2.

Not inserting into same
depth of soil.

1.

Leave time to adjust before
taking reading.

2.

Insert into same soil depth
each time.

​

Fill in the Blanks

Replace the underlined word to make the sentence correct.

A possible source of error when using a moisture meter is not taking samples at the same time of day.

Fill in the Blanks

Replace the underlined word to make the sentence correct.

To make results reliable, you should take many samples and calculate a whole number ratio.

Fill in the Blanks

Replace the underlined word to make the sentence correct.

When using a light meter, you should wipe the probe in between readings.

Fill in the Blanks

Replace the underlined word to make the sentence correct.

When measuring temperature, you use a pH meter.

Learning Intentions and Success Criteria

Learning Intention:

To learn about how energy is transferred through a food chain.
Success Criteria:

By the end of the lesson, I can:

• State how energy is lost in a food chain.

• Give the use of energy which is available at the next stage of a food

chain.

Food Chains and Energy

• Energy is transferred from one level to the next as you move up the

food chain.

• However, most of this energy is lost when this transfer happens.

caterpillar

leaf

bird

fox

How is energy lost in a food chain?

Energy is lost as:

1.Movement

2.Heat

3.Indigestible materials

Using energy for growth

• Growth is the only use of energy which is available at the next level

of a food chain.

Energy from

growth

Energy from

growth

• Because growth results in new tissue, when consumed, the energy

can be passed on to the next level.

Multiple Choice

Most of the energy is lost at each energy transfer in a food chain. What is one cause of this energy loss?

• Digested material

• Cell repair

• Movement

• Growth

Learning Intentions and Success Criteria

Learning Intention:

To learn about how food chains can be represented using pyramids.
Success Criteria:

By the end of the lesson, I can:

• State the definition of a pyramid of numbers.
• Draw a pyramid of numbers from a food chain.

• State the definition of a pyramid of energy.
• Draw a pyramid of energy from a food chain.

Pyramid of Numbers

• A pyramid of numbers shows the total number of organisms at each

level of a food chain/web.

Grass (Producer)

Wolf

Rabbit (Primary Consumer)

Secondary
Consumer

Irregular Pyramid of Numbers

• Sometimes, the number of organisms at each level results in an

irregular shaped pyramid of numbers.

• Remember: if it starts with a tree, the pyramid will look like a tree!

Caterpillar

Bird

Tree

Irregular Pyramid of Numbers

Another example:

Grass → Rabbits → Mites (parasite)

Parasite (flea)

Rabbit

Grass

Pyramid of Energy

• A pyramid of energy shows the total quantity of available energy

stored in the biomass of organisms at each level in the food
chain/web of an ecosystem per year.

• It looks like a regular pyramid as energy is lost at each level.

Grass

Rabbit

Parasite

10,000

1000

100

Multiple Choice

The diagram shows a pyramid of numbers.

Which letter shows the producers?

• A

• B

• C

• D

Multiple Choice

The diagram shows a pyramid of energy.

There is less energy at layer X because

• There are fewer organisms at each level in the food chain

• The organisms at level X are very small

• Energy is lost at each level in a food chain

• Energy is stored at each level and not passed on

Multiple Choice

The diagram shows 3 pyramids of numbers. Which pyramid could represent the food chain below?

Rose bush --> greenfly--> ladybird --> blackbird

• A

• B

• C