Distribution of organisms Flashcards
Why do organisms live in different places?
Because the environment varies.
What is a HABITAT?
Place where an organism lives.
What is the distribution of an organism?
Where an organism is found.
Where an organism is found its affected by?
Environmental factors.
Name 5 environmental factors?
Temperature. Availability of water. Availability of carbon dioxide/oxygen. Availability of nutrients. Amount of light.
Why might one organism be more common in one area than another?
Due to differences in environmental factors.
What ways can you study the distribution of an organism?
Transect.
Quadrats.
What does a quadrat tell you?
How common an organism is in two sample areas and then compare them.
What does a transect tell you?
The distribution of organism change across an area.
What type of organisms do quadrats study?
Small.
What is a quadrat?
Square frame enclosing a known area.
First step on how to use a quadrat?
Place 1m2 quadrat on the ground at a random point within the first sample area.
Second step on how to use a quadrat?
Count all the organisms within the quadrat.
Third step on how to use a quadrat?
Repeat steps 1 and 2 as many times as you can.
Fourth step on how to use a quadrat?
Work out the mean number of organisms per quadrat.
Fifth step on how to use a quadrat?
Repeat steps 1 to 4 in a second sample area.
Final step on how to use a quadrat?
Compare the two means.
How do you work out the population size?
Work out mean number of organisms per m2.
Multiply mean by the total area of the habitat.
Use transects to study the distribution of organisms…
Along a line.
First step on how to use a transect?
Mark out a line in an area you want to study.
Use tape measure.
Second step on how to use a transect?
Collect data along the line.
How do you count all the organisms along the line?
Counting all the organisms interested in that touch the line.
How else can you collect data with a transect?
By using a quadrat.
How do quadrats work with transects?
Placing quadrat next to or along the transect line.
Do this in intervals.
Transects can be used in any?
Eco system.
When collecting environmental data think about what 2 things?
Reliability.
Validity.
Make sure your results are?
Repeatable.
Reproducible.
How can you make your results more reliable?
Take a larger sample.
For your results to be valid they must be?
Reliable.
Name 2 things to do to keep results valid?
Control variables.
Use random samples.
