4.7 Energy Efficiency

• Losses in the owl is from respiration, producing energy for flight, digestion, movement, the nervous system. 
• All organisms finally die and are broken down by micro-organisms living on the dead and decaying remains of other micro-organisms. 
• 100Kj of grass energy represents grass eaten by the herbivore. 
• Mouse have to walk around and find their food and carry out the process of respiration. 
• 90Kj of energy left is lost from respiration and undigested food.

4.6 Energy and substances in food chains

• Bush grass is eaten by impala. 
• Bush grass is the producer Impala is the primary consumer leopard is the secondary
• consumer.
• Producer turns light energy into chemical energy - takes the form of organic molecules including carbohydrates, proteins and lipids --> what we call food.
• These molecules are composed of C-H bonds, C-O bonds, C-C bonds, O-H bonds and C-N bonds - ALL represent energy. 

4.5b Food Webs

• Food webs allow better description of the ecosystem.
• Food web allows us to show organisms feeding at different trophic levels. 
• Organisms can have multiple predators.
• Organisms may be feeding on multiple pray.
• Results in food chains becoming linked.

4.5a Food Chains

•  Food in China links together producer to the 1st consumer, 2nd consumer and 3rd consumer. 
•  Only one organism per trophic level.
•  Food chain cannot show an organism being an omnivore. 
•  Cannot show them feed at more than 2 trophic levels. 
•  Food chains show the flow of matter and energy. 

4.4 Trophic Levels

• Trophic means to feed.
• Carrot plant>Photosynthesis>Producer.
•  Producer turns light energy into chemical energy.
•  Primary Consumer takes in the chemical energy of the plant and changes it into chemical energy of the fly.
•  All organisms die and are then broken down by decomposers of fungi and bacteria. 

4.3 Quadrates samples

• The sample needs to be random (bias). 
• The second part of the sample is that it needs to be representative (large).
• A sample needs to be big enough so the estimate has to be close to the real population. 
• The grid system is going to work like the x,y coordinates on a graph you would draw.
• The random numbers are used to generate a number for the x and y coordinates and will tell us where to take a sample from. 

4.2 Quadrates

• Quadrates are used to estimate the population size of an organism in two different areas.
• All ecosystems are made up of a number of populations which formed the community. 
• The technique is called quadrating, it is based on squares and can be made from an material.
• They form square grids which can consist of 0.25 meter or 1 meter. 
• Quadrates are a method of sampling different locations so populations can be compared in two different locations.

4.1 Ecosystems

• A community of organisms consist of a population of different species. 
• The habitat includes the non biological factors.
• The environment could have the cycle of daylight with dark, the temperature, rainfall, humidity and slope of the land. 
• All the factors have something in common; they are all non biological. 
• The community which is made up from different species interact with each other.