Transcript 3.3 Powerpoint

Decomposers
Learning Intention: Explain that decomposers such as
bacteria and fungi recycle nutrients vital for life
Success Criteria:
• Define the term decomposer
• Identify examples of decomposers
• Describe how decomposers breakdown materials
• Set up a composter to see food decomposing
Starter Activity:
What does the following word mean to you?
Nutrient
Mind map as many ideas as you can think of
related to this word.
What are decomposers?
• Decomposers are
organisms that get their
energy from dead plant
and animal material.
• To get the energy from
the material, they break
down the large complex
chemicals.
• Some of the nutrients
then get returned to the
environment.
Can you identify decomposers?
A. Field Mouse
B. Earthworms
D. Blackbird
E. Fungi
C. Bacteria
F. Potatoes
Can you identify decomposers?
B. Earthworms
E. Fungi
C. Bacteria
Decomposers
Some examples of
decomposers are:
Earthworms
Bacteria
Fungi
Decomposers
• Bowl of Fruit Decomposing
• Dr. Yan's Decomposition Timelapse
Decay
• This process is decay
or decomposition, and
it releases nutrients
back into the
environment ready to
be reused by other
organisms.
How to make compost
The aim of this experiment is to make
compost using food and garden waste
from school and home.
How to make compost
• To make your compost bottle you will need:
• Two 2 litre plastic (water or juice) bottles with
caps
• Sharp scissors
• Tights
• Waterproof tape
• A rubber band
Follow the instruction card to make your
composter.
Multiple-choice quiz
Rot Box
In 2011, Edinburgh Zoo set up a ‘Rot Box’.
The Rot Box experiment looked at decay
and rot. Filmed over two months, the Rot
Box captured how food and waste decayed
in a kitchen and a garden.
Rot Box Webcast (40 minutes)
The Nitrogen Cycle
Learning Intention:
To understand how nutrients are recycled in the
environment
Success Criteria:
• Explain the importance of the nitrogen cycle to
the environment
• Explain the importance of decomposers in the
environment
• Identify examples decomposers
Nutrient Cycles
• Living organisms need certain nutrients
to stay alive e.g. nitrogen, oxygen,
carbon, mineral salts.
• These nutrients are often in limited
supply so it is important that they are
recycled within the ecosystem.
Activity 1
• Watch the video clip and write down
three facts.
• Nitrogen Cycle
Why do we need nitrogen?
• All living things need nitrogen to make
protein.
• Plants get nitrogen by taking in nitrates
from the soil and converting them into
protein.
• Animals obtain nitrogen by eating plants
or other animals.
What is the nitrogen cycle?
Labelling the nitrogen cycle
How nitrogen gets into the soil
• Nitrogen in the soil is in
the form of nitrates.
• Decomposers (bacteria
and fungi) break down
dead plants and animals
and this adds nitrate to
the soil.
• Other bacteria in the
soil (nitrogen fixing
bacteria) absorb
nitrogen from the air
and make it into
nitrates.
Nitrogen in the air
Nitrates in the soil
How farmers add nitrogen to the
soil
• Fertilisers contain nitrates,
so when farmers use these,
it adds nitrate to the soil.
These could be natural
fertilisers like manure or
chemical fertilisers.
• Some special plants, called
leguminous plants, can make
nitrates for themselves
using nitrogen in the air.
• Examples of such plants are
peas, beans and clover.
• Farmers sometimes grow
clover in a field, then plough
it into the soil. This
increases the nitrogen in
the soil and means that
crops grown after this will
be better.
Leguminous plant fixing nitrogen
How nitrogen is lost from the soil
• Some bacteria convert nitrates
into nitrogen gas and release it
into the air.
• Rainwater can carry nitrates
away from the soil. This is called
leaching.
• When farmers remove crops, and
do not allow any plants to
decompose, this reduces the
nitrates in the soil. This is why
fertilisers need to be used.
Nitrogen in the air
Nitrates in the soil
Nitrogen Cycle
• Twig Video: Nitrogen Cycle
• StudyJams
The Nitrogen Cycle
Fact finding mission: What happens at each of the points on the diagram?
Work with your partner to find out the 5 key points of the nitrogen cycle
1
2
5
3
Nitrates
4 in soil
The importance of the nitrogen cycle
Nitrogen fixing bacteria
convert nitrogen gas into
nitrates
Nitrates in soil
• The nitrogen cycle is very important to all living things.
• Nitrogen is needed to make proteins.
• Proteins are used to make lots of different parts of a living thing.
The Nitrogen Cycle Game
In this game you will be a molecule of
nitrogen in the nitrogen cycle. Find out
all the places you travel to. Your teacher
will explain what to do.
Nitrogen Cycle Game
Write in each circle where you travel to.
The Nitrogen Cycle
Learning Intention:
To understand the importance of nitrogen
to a plant
Success Criteria:
• Investigate the effects of no nitrogen on
a plant
Investigating the effect of
fertilisers on the growth of
plants
Aim : To find out how different levels
of fertiliser affect the growth of
plants
Setting up the minipots
•
-
You will need:
a set of minipots
4 wicks
growing mix
a spatula
fertiliser pellets
12 seeds
a dropper
a sticky label
Setting up the minipots
This is the order in
which you put things
in the pot. (from the
bottom up)
growing mix
seeds
growing mix
fertiliser pellets
growing mix
wick
1
0
3
2
Each minipot is the
same, except the
number of fertiliser
pellets.
Setting up the minipots
1.
2.
3.
4.
5.
6.
7.
8.
9.
Wet each wick thoroughly. Put one wick through the hole in
the bottom of each minipot. Half of the wick should be
outside and half inside.
Cover the hole under one minipot with your finger and half
fill with growing mix. Push down gently into the corners.
Repeat for the other 3 pots.
Mark the numbers 0, 1, 2 and 3 on the side of each pot.
Add this number of fertiliser pellets to the pots.
Add more growing mix to fill to the top. Press down gently.
Add 3 seeds to each minipot. Cover with more growing mix.
Label the pot with your initials.
Water from above using a dropper until water drips
through.
Place the minipot on the box under the lights for 5-7 days.
Compare the growth of each set of plants.
The contents of each minipot
growing mix
3 seeds
growing mix
fertiliser pellets –
add none, one, two
or three
growing mix
wick
Keeping the minipots watered
minipots
capillary matting
water
reservoir
wick to soak
up water
from
reservoir
The Nitrogen Cycle
Learning Intention:
To understand how nutrients are recycled
in the environment
Success Criteria:
• Describe the role of microorganisms in the
nitrogen cycle
• Define the term nitrogen fixation
Starter
• Draw out on the large show me boards
the nitrogen cycle.
Microorganisms, called microbes for short, are very
small living things that are often only made up of one
cell.
Bacteria and fungi are examples of microbes and they
have very important jobs in the nitrogen cycle.
Looking at Microorganisms
1. Look at some examples of bacteria
using a microscope
Microscope tips
1. Always start with the lens with
the lowest magnification (x4)
2. Use the big wheel to get the
slide into focus
3. Use the small wheel to fine tune
the focus and see your image
more clearly
2. Draw what you see on a piece of paper using a sharp pencil
What do microorganisms do in the
nitrogen cycle?
• Microorganisms called
bacteria are needed in the
nitrogen cycle.
• Special bacteria found in
the soil change nitrogen in
dead animals and plants into
nitrates.
What do bacteria do in the
nitrogen cycle?
• Special bacteria
found in the roots
of some plants carry
out a process called
nitrogen fixation.
• During this process
the bacteria change
the nitrogen in the
air spaces in the soil
into nitrates.
Nodules
The roots of a nitrogen
fixing plant, showing its root
nodules. These nodules
contain the nitrogen fixing
bacteria.
Root Nodules Practical
• The root nodules of the broad bean
contain nitrogen-fixing bacteria.
Root Nodules Practical
• Wrap damp paper towel
round the inside of the
jar and place the bean
seed between the damp
paper and the jar.
• The bean should sprout in
4 days.
• Examine the roots
carefully for the
presence of nodules.
Find someone who…
1. Take a piece of A4 paper and fold it in half three times
2. When you unfold it you should have eight squares
3. Find a different person to tell you the answer to each of the questions below:
1. Can name a
nutrient that is
recycled in the
environment
2. Can explain
3. Name an
why nitrogen is example of a
important to
decomposer
the environment
3. Say what
decomposers do
in the nitrogen
cycle
4. Can give an
example of a
microorganism
involved in the
nitrogen cycle
5. Can say what
nitrogen
fixation means
8. Can tell you
two places
nitrogen is
found in the
environment
7. Can tell you
another form of
nitrogen in the
environment