| What are abiotic factors? | Non-living factors of the environment e.g. temperature |
| What are biotic factors? | Living factors of the environment e.g. food |
| What is an ecosystem? | The interaction of biotic and abiotic parts of the environment |
| What is transferred when organisms eat other organisms? | Energy |
| What are populations usually limited by? | Amount of food available |
| Method to use quadrats to study the distribution of small organisms | Place 1m^2 at random point within sample area
(Use a random no. generator to pick coordinates within area)
Count all organisms inside quadrat and record no. and types
Repeat as many times as possible
Work out mean number of organisms per quadrat
Repeat steps above in a second sample area
Compare two means |
| Method to use transects to study distribution of organisms along a line | Mark out a line in the area of interest with a tape measure
Collect data along the line either using quadrats at intervals or counting organisms that touch the line
Record the data
Repeat steps above and then compare organisms on different transects |
| Three environmental changes that affect organism distribution | Water availability, temperature, atmospheric gases |
| What are these environmental changes caused by? | Seasonal factors, geographic factors and human interaction |
| What is the water cycle? | The sun makes water evaporate turning it into water vapour
Water transpires into from plants contributing to vapour
Warm vapour rises and cools condenses to form clouds
Water falls from clouds as precipitation onto land
It then drains into the sea and the cycle begins again |
| What is the carbon cycle? | CO2 is removed from the environment by green plants and algae during photosynthesis
When respiration occurs some carbon is returned to the atmosphere
When plants and algae are eaten by animals the carbon moves through the food chain
Some carbon is returned to the atmosphere when animals respire
When plants, animals and algae die microorganisms (detritus feeders) feed on the remains
When these respire carbon is returned to the atmosphere
The process begins again |
| What affects the rate of decay? | Temperature, oxygen availability, water availability, number of decay organisms |
| What is biogas? | Gas (mainly methane) produced from anaerobic decay of waste material |
| Brief method to investigate decay | Add lipase solution to test tube
Add milk to a different test tube
Add phenolphthalein indicator to the milk
Add sodium carbonate to the milk turning it alkaline
Put both test tubes in a water bath until they reach 30 degrees
Add a set volume of lipase solution into the milk solution and start the stopwatch
The enzymes will start to decompose the milk beginning a colour change
Once the solution has change colour stop the stopwatch and record the time of the colour change
Repeat the experiment three times to ensure reliability
Repeat the experiment at different temperatures and then calculate the rate of decay for each |
