4.7 Energy efficiency

4.7 Energy efficiency

Explain why only about 10% of energy is transferred from one tropic level to the next.

4.6 Energy and substances in food chains

Understand the transfer of substances and of energy along a food chain

4.6 Energy and substances in food chains

Understand the transfer of substances and of energy along a food chain

Bush grass (producer) - Impala (primary consumer) - leopard (secondary consumer) - if ever eaten by lion (tertiary consumer)

Producer - converts light energy into chemical energy. Chemical energy takes form of organic molecules including carbohydrates, proteins, and lipids. (Food to impala, leopard, and lion). These molecules are composed of:

C-H

C-O

C-C

O-H

C-N

All these bonds represent energy. (Carbon, hydrogen, oxygen and nitrogen are substances/matter)

As the bush grass photosynthesises, it creates organic molecules which are the substances which contain energy that came from sunlight. The impala consumes this for growth, respiration, and life processes. The cheetah then eats it and then processes these molecules by reorganising it.

Each stage of the food chain contains the substances of matter and energy (bonds between elements)

4.5b Food Webs

4.5b Food Webs

Understand the concepts of food chains, food webs, pyramids of number, pyramids of biomass and pyramids of energy transfer

The food web enables us to provide a better description of the ecosystem.

Ecosystem is a community of organisms which are interacting, in this example they are FEEDING

An Advantage is that it allows us to see organisms feeding at different trophic levels. However its consequences are that:

1) Organisms can have multiple predators

2) Organism may feed on multiple preys

3) Results in food chain becoming linked

You can see that the Hawk can either be the secondary or tertiary consumer.  It is a multiple predator

The slug is the prey to badgers, small birds and hedgehogs

The fox feeds on the rabbit, mice and shrew. This causes it to become linked.

Some food chains have 2 or 3 links to them.

 

4.5a Food Chains

4.5a Food Chains

Understand the concepts of food chains, food webs, pyramids of number, pyramids of biomass and pyramids of energy transfer

Food chains link the producer to the primary, secondary and possibly tertiary consumer.

1 organism per trophic level (in a food chain an organism being an omnivore, or having more than 2 trophic levels cannot be shown)

Food chains show the flow of matter and energy

4.4 Trophic Levels

4.4 Trophic Levels

Recall the names given to different trophic levels to include producers, primary, secondary and tertiary consumers and decomposers

Trohpic- to feed. Recall the names given to different feeding levels

Carrot plant (photosynthesis) - carrot fly (herbivore) - flycatcher (carnivore) - top carnivore (eating the carnivore). Other names exist in ecology to describe the different feeding levels

Carrot plant: producer (turn light energy into chemical energy)

Carrot fly: primary consumer (takes in chemical energy of plant and turns it into the chemical energy of the fly. Changing the form of chemical energy)

Flycatcher: Secondary consumer (changing chemical energy from one form to another)

Sparrow Hawk: Tertiary consumer (eats secondary consumers, take in molecules from the fly catcher and then turn it into a more suitable molecule better adjusted to them)

At some stage all of the organisms die. They are then broken down by special organisms known as DECOMPOSERS. 2 examples of decomposers are fungi and bacteria. They are important as they recycle the molecule. They break down the more complex molecules (nitrates and phosphates)

4.3 Quadrates samples

4.3 Quadrates samples

Describe  the use of quadrats as a technique for sampling the distribution of organisms in their habitats

4.2 Quadrates

4.2 Quadrates

Recall the use of quadrats to estimate the population size of an organism in 2 different areas.

4.1 Ecosystems

4.1 Ecosystems

Understand the terms: population, community, habitat and ecosystem