(I)GCSE Topic 4.7 Energy Efficiency

-A simple food chain would need a producer (grass), which would be eaten by the primary consumer (mice), which would be eaten by the secondary consumer (owl),
-The grass has 100kj which will be eaten by the mice but only 10kj from the original 100kj becomes part of the mice because it can only digest certain parts of the plant.
-The rest of the 90kj will be lost through respiration or faeces (undugested marerial).
-When the owl eats the mice, it will only be able to take in 1kj from the 10kj of the mice.

(I)GCSE Topic 4.6 Energy and Substances in food chains

-Producer turns light energy into chemical energy and this chemical energy takes the form of Organic Molecules including: carbohydrates, protiens, lipids.
-These molecules in the producer is food to the primary consumer; the moleculs in the primary consumer is food to the secondary consumer; the molecules in the secondary consumer is food to the tertiary consumer.
-These moleculs are composed of:
  Carbon - Hydrogen
  Carbon - Oxygen
  Carbon - Carbon
  Oxygen - Hydrogen
  Carbon - Nitrogen bonds
-These bonds all represent energy
-As the plant carries out photosynthesis, it creates the organic molecules which are the substances and contains the energy which was turned from sunlight into chemical energy.
-The substances/matter and energy are passed along the food chain.

(I)GCSE Topic 4.5 b) Food Webs

-Food Web allows us to provide a better description of the Ecosystem.
-Ecosystem is composed of the community of organisms which are interacting.
-Food Web allows us to show organisms feeding at different trophic levels.

Consiquences of feeding at different trophic levels:
  -Organisms can have multiple predators
  -Organisms feeding on multiple prey
  -This results in the foodchain becoming 'linked'.

(I)GCSE Topic 4.5 a) Food Chains

-A food chain links together the Producer, Primary Consumer, Secondary Consumer, Tertiary Consumer.

-1 organism shown per trophic level

-In a food chain you cannot show an organism being an omnivore,  or feeding at 2 trophic levels.

-Food Chains show the flow of matter and energy.

(I)GCSE Topic 4.4 Trophic Levels

- Trophic = To Feed

- Photosynthesis > Herbivore >  Carnivore > Top Carnivore

-Photosynthesis / Producer
- Herbivore / Primary Consumer
- Carnivore / Secondary Consumer
- Top Carnivore / Tertiary Consumer

- Producer turns light energy into chemical energy
- Primary Consumer takes in the chemical energy of the plant and turns it into the chemical energy of the Primary Consumer.
- Secondary Consumer changes the chemical energy of the Primary Consumer into chemical energy of the Secondary Consumer.
- Tertiary Consumers take in the molecules of the Secondary consumer and turns it into a molecule suitable for the Tertiary Consumer.

(I)GCSE Topic 4.3 Quadrates Samples

Use of Quadrates as a Technique for sampling the distribution of organisms in their habitats:
- Use the Quadrate technique to sample the population (Daisy) in a area.

The sample has to be:
- picked at random so there is no Bias.
- representative - has to be a large amount so the estimate of the population has to be as close to the true population as possible.
- The bigger the number of representative sample, the better.
- 10 quadrates / 10% of the actual area

Estimate the population of (Daisys) in the field:
Compare te number of (Daisys) in two or more different areas:

Add up the number of (Daisys) per m2, divide by the number of quadrates, = number of (Daisys) per m2 

(I)GCSE Topic 4.2 Quadrates

- Quadrates are used to estimate the population size of an organism in two different areas.
- First thing you need to do is count the number of individuals in the population.
- Quadrating is based on squares and these squares can be made up of anything including wood, string, or metal.
- Grids can measure from 0.25m up to 1m
- The Quadrate is used to sample the area. You can take a sample from an area and count the number of individuals inside the area and this would be repeated a number of times to gain an estimate of the population size

-Quadrates are a method of sampling different locations so that populations can be compared within the two different locations.

(I)GCSE Topic 4.1 Ecosystems

-Habitat refers to
  - Daylight/dark
  - Temperature
  - Rainfall
  - Humidity
  - Slope of the land

-Community refers to
  - Population - number of individuals if each species
  - Species - breeding fertile offspring
  - Interacting - feeding (food chains/ food webs)

-Community of organisms is made up of a population of different species interacting.
  - Population of different species is the number of individuals of a particular species.
  - Interacting if the feeding of the animals.
  - Species is the organisms which reproduce to give fertile offspring.

SUMMARY
-Ecosystem is a community of organisms in a particular habitat.
-The community is made up of different populations of the different species interacting within that habitat.

TOPIC 4 (I)GCSE ECOLOGY