Life on Earth - Measuring

Question 1

Describe a Quadrat and its features

Answer 1

• Standard shape (usually a square of 0.25m² area) researchers use to look closely at a known area.
• Measures slow moving animals/ plants
• Several placed randomly to make estimate more reliable
• Limitation = Can’t be used for fast moving animals/plants

Question 2

List 2 rules that must be followed when using quadrats

Answer 2

• exclude organisms that are touching two sides of the square
• include organisms touching the other two sides

(the sides are selected by the researcher)

Question 3

Identify 3 errors that can be made when using quadrats

Answer 3

• Not placing the quadrat randomly
• wrong size being used
• plants that are found are not identified correctly.

Question 4

• Describe a Pitfall trap
• Describe its features

Answer 4

• Used to sample small invertebrates on the soil surface of leaf litter.
• Animals that fall into the trap and cannot get out are therefore sampled
• Several placed randomly to make the estimate more reliable
• Limitations = Can’t be used to sample larger animals or ones that fly, trap size can be limiting.

Question 5

The reliability of pitfall trap experiments depends on…

Answer 5

…number of traps set

Question 6

Identify 2 errors that can be made when using pitfall traps

Answer 6

• traps are not placed randomly
• not covering the trap well (allows predators to catch prey in traps)

Question 7

Draw each of the following:
* pitfall trap
* quadrat

Answer 7

CHECK SUMMARY SHEET FOR LOE