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Inquiry Activity
• In groups of 2-3, you have five minutes to make a list of all of the types of organisms, including plants, humans, animals, insects etc that you have seen in a specific location.
• Rainforest• Tundra!
Inquiry Activity
• Make a diagram that shows how the organisms that you listed interact with each other.
• Who eats who/what?• Where do these organisms live?
Think About It
1. Which organisms on your list provide energy or nutrients to the others? 2. What would you expect to happen if all the plants in your diagram died? EXPLAIN your answer.3. Why is it difficult to make accurate predictions about changes in communities of organisms?
3.1: What is ecology?
• Ecology is the scientific study of interactions among organisms and between organisms and their environment
• Etymology (word Root): eco comes from the Greek oikos which means house.
The Biosphere
The biosphere contains the combined portions of the Earth in which all life exists, including land, water and air or atmosphere.
It extends 8 km above the Earth’s surface and as far as 11 km below the surface of the ocean.
Autotrophs/ Producers/ (Trophic Level 1)
Food energy is most commonly produced from light energy through photosynthesis
Some autotrophs can produce food energy without light, instead using chemicals like hydrogen sulfide. These autotrophs use a process called chemiosynthesis.
Chemotrophs
Some autotrophs can produce food energy without light, instead they use chemicals like hydrogen sulfide. These autotrophs use a process called chemiosynthesis.
Let’s meet some…Deep Sea ChallengerCompare chemosynthesis with photosynthesisGiant Amoeba
Heterotrophs/ Consumers (and decomposers)
Organisms that rely on other organisms for food are called heterotrophs or consumers.
Decomposers can be detrivores or saprotrophs
• detritus 1• detritus 2Decomposers (bacteria and fungi) recycle nutrients (organic matter and other essential elements) in an ecosystem
GRASS
A plant - makes its own food
RABBIT
An animal that eats
plants
FOX
An animal that eats other
animals
The arrows
show the food chain
GRASS
A plant - makes its own food
RABBIT
An animal that eats
plants
FOX
An animal that eats other
animals
The plant is a
‘producer’PRODUCER
GRASS
A plant - makes its own food
RABBIT
An animal that eats
plants
FOX
An animal that eats other
animals
The rabbit is a ‘consumer’ - a herbivore
or plant-eater
PRODUCER
CONSUMER
GRASS
A plant - makes its own food
RABBIT
An animal that eats
plants
FOX
An animal that eats other animals
The fox is also a
‘consumer’ - a predator or meat-
eater
PRODUCER
CONSUMER
CONSUMER
Food chains and food webs work in the same way in the
sea ...
… but the plants and animals look a bit different!
Out in the ocean, there is no grass or
trees
The plants are tiny ALGAE - you need a microscope to see
them
ALGAE
Microscopic plants - make their own food
COPEPOD
A tiny animal that eats plants
FISH
An animal that eats other
animals
This is a food chain in the
ocean
A simple food chain - whale eats krill
eats algaeCopepods also eat
algae, and are eaten by krill
Fish eat krill and copepods
Squid eat fish and krill
Seals eat squid
and fish
This food web contains 7 types of living things, and 9 food chains
Not all energy from food is turned into tissue ‘growth’
• A lot of food energy is used to provide energy for heat, warmth, cellular respiration…
• Some is indigestible, and is ‘lost’ (e.g. cellulose, teeth, claws, skin…)
An example: krill feeding on algae
70 grammes of algae eaten per
day 10 grammes - about 15% - is
indigestible
50 grammes of food are used to provide
energy for swimming and catching more food
This leaves 10 grammes of
food that can be used for
growth
70 grammes
‘in’
= 100%
50 grammes
plus
10 grammes
‘to waste’
= 85% of food eaten
10 grammes to growth
= 15% of food eaten
A large blue whale will eat 3 tonnes of
krill each day
The amount of growth will be 120 kilogrammes -96%
of the food has ‘gone to waste’
In the oceans, both the plants and the herbivores are small. There are great size differences
between herbivores and predators
We can understand the size differences more easily if we match each living thing to familiar objects. Here, we magnify each 1000 times
Making each alga cell 1000 times bigger means that it is about the size of a squash ball
Making the krill 1000 times bigger means that it becomes
as long as a small bus
Making the whale 1000 times
bigger means that it is still
huge - it would stretch across
the Isle of Wight
Not all energy from food is turned into tissue ‘growth’
• A lot of food energy is used to provide energy for heat, warmth, cellular respiration…
• Some is indigestible, and is ‘lost’ (e.g. cellulose, teeth, claws, skin…)
• This happens at EACH LINK in the food chain…
For 100 TONNES of algal growth…
• You get 15 tons of new krill growth• And only 600 kg of new whale growth
Now, for 100 tonnes of algal growth
• There is 1 kg of seal growth• Which means that 99.999% of the energy of
the algae eaten by the copepods has been ‘lost’
A food chain links plants and animals in a habitat
All food chains start with a plant = producer
You have seen that -
Food webs on land and in the ocean are similar
In the ocean, plants and herbivores are small
You have seen that -
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