Random Sampling and Quadrats

What is a square called that we use to sample populations?

• grid

• quadrat

• cube

• quarter

What type of population would you ESTIMATE using a quadrat?

• 
• 
• 
• 

Limpets were found in 25 out of 50 quadrats. What percentage of quadrats contained limpets?

• 100%

• 25%

• 50%

• 75%

Why do scientists use sampling techniques to gather population data rather than counting everything?

• scientists are lazy

• sampling is more efficient and achievable

• sampling is more accurate

• scientists prefer estimations

• sampling is cheaper

Tn 1m² quadrats were placed in a 40m² field. On average 2 snails were found in every quadrat. Estimate the population size of the whole field.

• 2

• 10

• 40

• 80

• 20

Can a quadrat be used on a large land organism that moves around in a herd?

• yes - use a quadrat

• no - you can't use a quadrat

Which of the following is true about quadrats?

• quadrats should be placed randomly so that a representative sample is taken

• you should look at the results from several quadrats in an area to reduce the effect of an unusual distribution

• the results are more reliable when you look at the results from many quadrats

• All the above are true

What is the best way to place a quadrat?

• Place it where you like

• Divide the sample area into a grid and use a random number generator to choose a square.

• Throw the quadrat so it's random

• Divide the sample area into a grid and choose a square.

An area of 5m² was sampled using a quadrat to find a total of 10 sunflowers. If the area of the field was 200m² , what is the estimated number of sunflowers in the field?

• 50

• 20

• 40

• 400

When sampling organisms in a certain area using a quadrat you also need to know...

• Area of the quadrats

• Sum of area covered by quadrats and the field

• Area of the field & area covered by quadrats

• Area of the field