B2 - Distribution of Organisms

Question 0

What are the 5 factors that affect the distribution of an organism?

Answer 0

Temperature

Availability of water

Availability of oxygen and carbon dioxide

Availability of nutrients

Amount of light

Question 1

What is the distribution of an organism?

Answer 1

Where an organism is found

Question 2

Describe how you compare how common an organism is in 2 different areas

Answer 2

Place a 1m^2 quadrat on the ground at a random point within the first sample area

Count all of the organisms in the quadrat

Repeat the last 2 steps many times

Calculate the mean number of organisms per quadrat in the first area

Repeat all of the last steps for the second area

Compare the 2 means

Question 3

How do you work out the population size of an organism in a sample area?

Answer 3

Work out mean number of organisms per 1m^2 quadrat

Multiply mean by the area of the habitat in m^2

Question 4

Describe how you can show how organisms are distributed along a line

Answer 4

Mark out the line to study using a tape measure

Collect data along line using quadrats

Question 5

What 2 things do you have to do to make results more reliable?

Answer 5

Make sure they are repeatable and reproducible

Use a large sample size (more representative of population)

Question 6

What 3 things do you do to make results more valid?

Answer 6

Control all variable except for the one you are testing

Make sure the experiment actually shows how the actual independent variable affects the dependent variable

Use random samples to reduce bias (throw quadrat randomly etc.)