Download Completed Environment Pupil Notes

The Kelso High School
Biology
Environment
Name……………………..... Class………..
Keep this booklet safe – you will need it for revision.
Environment
Use this table as a checklist for your revision.
= core
= challenge
Understood
and learnt
Level
Need to do
more work
Need to get help
- see my teacher.
You need to be able to……
Give the definitions for ecosystem, habitat, population
and community.
Identify 2 abiotic and 2 biotic factors
Give an example of a technique which could be used
to measure an abiotic factor and describe its use.
Identify a possible source of error of that technique
and explain how it might be avoided.
State the effect of one abiotic factor on the distribution
of organisms.
Explain how abiotic factor affect the distribution of
organisms.
Identify organisms using branching and paired
statement keys.
Construct branching and paired statement keys.
Give an example of a technique which could be used
for sampling organisms and describe its use.
Identify a possible source of error of that technique
and explain how it might be avoided.
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Give the definitions for producer, consumer,
herbivore, carnivore, omnivore, primary consumer,
secondary consumer.
Give an example of a food chain and a food web.
State that the arrows in a food chain indicate the
direction of energy flow.
State 2 ways in which energy can be lost from a food
chain.
Explain the effects of removing one species on the
remaining organisms in a food web.
State that the growth of a population depends on the
birth and death rate.
Describe and explain the growth curve of a population
under ideal conditions.
State 3 factors which can limit the growth of a
population.
State that competition occurs when organisms have a
need for the same resources.
Describe some effects of competition.
Date of ‘Environment’ End of Unit Assessment:
………………………………….
Remember, in addition to testing your knowledge the assessment will include
problem solving questions, eg graph drawing, calculations, etc.
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Ecosystems
Term
Definition
Example
- a natural biological unit made up of
living and non-living parts
- tropical rain
forest, freshwater
loch, etc
- place where an organism lives
- pond, field, etc
- all the organisms of one species that
live together in an ecosystem
- frogs in a pond,
rabbits in a field
- all the plants, animals and bacteria
that live together in an ecosystem.
All the frogs, fish,
plants, bacteria
etc that live in a
pond.
Ecosystem
Habitat
Population
Community
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Factors Affecting Ecosystems
Many things can affect ecosystems.
Living things which can affect ecosystems are called __abiotic________
factors. These include:

___Light intensity_______________________

___soil pH_____________________________

___soil moisture, etc_____________________
Non-living things which can affect ecosystems are called __biotic__________
factors. These include:

___food availability_______________________

___number of predators___________________

___diseases present_____________________

__competition __________________________
It is useful to measure abiotic factors and various pieces of equipment can be
used to do this. To make sure that your measurements are reliable the
equipment must be used properly.
Abiotic
Factor
Light
Intensity
Soil
moisture
Equipment
Used
Sources
of
Error
Ways in Which
Error is
Minimised
Standing in front of the
sensor
- don’t stand in front of
the sensor.
- probe not left long
enough to monitor the
moisture level.
- leave probe in soil for
a few seconds
- probe not wiped after
each sample.
- wipe probe after
each reading
Light meter
Moisture
Meter
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Identifying Organisms
If you are studying the populations and communities in ecosystems you need
to be able to identify the plants and animals that are there. To do this you can
use a key.
There are two types of key:

_____Branching key__________________________________

_____Paired statement key____________________________
A Branching Key:
Leaves
Prickles
(HOLLY)
No Prickles
Jaggy Edge
(ELM)
Smooth Edge
Lobes
(OAK)
No Lobes
(BEECH)
A Paired Statement Key:
1. Leave with prickles………………………HOLLY
Leave without prickles…………………..Go to 2.
2. Jaggy edge………………………………..ELM
Smooth edge……………………………..Go to 3.
3. Lobes……………………………………...OAK
No lobes…………………………………...BEECH
Use the keys to identify the following leaves:
___beech______
__________oak__________
____elm_________
_____holly__________
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Sampling Organisms
If you are studying plants and animals in an ecosystem you may need to find
ways of capturing and counting them. There are many different ways to do
this depending on the animal or plant you are studying.
A pitfall trap is used to collect animals that live on the soil surface and
amongst leaf litter.
_____lid___________
___pot_______
__alcohol_________
Avoiding Errors When Using a Pitfall Trap

____Several____________ pitfall traps should be set up to give
reliable results.

The opening of the trap should be disguised by a ___lid_________so
that trapped animals are not seen and eaten by predators.

A preservative liquid, eg ___alcohol______________ is put in the
bottom of the trap to humanely kill and preserve the animals.
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It is unlikely that you would be able to count all of the plants and animals in an
ecosystem because this would take too long. Instead, small samples which
represent the whole ecosystem are taken
Plants are often sampled in this way using ____a quadrat______________.
This is a square of a known area which is randomly placed on the site being
studied. The plants inside the quadrat are identified and counted. From this
information the estimate of the number of a certain plant can be calculated.
__quadrat______
__area___
__plant______
Avoiding Errors When Using a Quadrat

Make the results more _reliable_________ by using a bigger number
of quadrats.

Place the quadrats at ___random_________ over the area being
studied, don’t choose where to place it.

Make a rule to decide what to do with plants that fall partly in or out of
the quadrat, eg more than half the plant in the quadrat counts, more
than half out the quadrat doesn’t.
Out
In
Out
In
In
Out
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Energy Flow Between Organisms
There are several terms that can be used to describe the way organisms
obtain their energy.
Term
Definition
Example
An organism that can produce its own
Oak tree,
food. Usually a green plant that
dandelion
Producer
produces its own food using energy
from the sun by the process of
photosynthesis.
Consumer
Any organism that cannot produce its
own food, instead they eat other
organisms to get their energy.
Sheep, fox, lion,
giraffe
Any animal that only eats plants to get
their energy.
Rabbit, deer, etc
Any animal that eats other animals to
get their energy
Fox
Tiger
Herbivore
(or primary
consumer)
Carnivore
(or secondary
consumer)
Human being, fox,
badger
Omnivore
An animal that eats both plants and
animals to get their energy.
The way in which energy passes from plants to animals and then to other
animals can be shown by a food chain.
There are two rules when you make your own food chains:

All food chains start with a ___producer________________

You must show the __arrows______________ in a food chain. The
arrows in a food chain go from food to feeder and represent the
direction of energy flow.
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As energy is passed along a food chain each of the organisms uses some of it
for its own needs, eg moving, keeping warm, etc. This means that energy is
lost at each link in the food chain and the only energy that can be passed to
the next link in the food chain is that which is part of the body of the organism
itself.
Approximately ___90______% is used by the organism and not available to
the
next link in the food chain, so only about ___10_____% of the energy can be
passed on.
Most animals eat more than one kind of food and so in any ecosystem food
chains connect to form a food web.
All food webs are delicately balanced. The removal of one organism from the
food web can have a serious effect on others.
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Population Growth
The size of most populations tends to stay roughly the same. The size of a
population stays the same as long as the birth rate is the same as the death
rate.
1. Little or no increase as
the population starts to
reproduce.
2. Rapid population
increase.
3. No more increase as
population numbers are
checked by something.
Time
In most populations there is something which prevents a population explosion.
Limiting factors are things that prevent a
population from growing any larger. For
example, 10 rabbits may live in a habitat
that has enough water space to support
20 rabbits, but if there is only enough
food for ten rabbits, the population will
not grow any larger. In this example,
food is the limiting factor.
Food is not the only factor that may limit
population growth. For example, there
may be enough food to support a
thousand birds in a certain area, but only
suitable nesting sites for one hundred.
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Competition
If organisms use the same resources the competition will occur.
Animals compete for:
Plants compete for:
__food______________
__sunlight___________
__water_____________
_space_____________
__mates____________
__water_____________
__nesting sites, etc___
__nutrients in the soil___
When competition occurs some organisms will be more successful than
others. These organisms will be more likely to survive.
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