Sampling techniques Flashcards
1
Q
What problems do biologists meet when investigating where organisms live
A
- many different organisms
- live all over the place
2
Q
Techniques biologists use to collect info
A
- collect organisms
- count the number of organisms in each species
- record where the organisms were found
- collect accurate data
- collect the data fairly
- collect reliable data
3
Q
Quadrats
A
- square frames of a standard area
- put on the ground to define an area
- the number of organisms in the frame can be counted
4
Q
Transect lines
A
- tapes that are laid across the environment
- count organisms or plants that touch the tape
- alternatively, place quadrats along tape at regular intervals to record distribution
5
Q
Nets
A
- used to catch animals
- count and record number caught
6
Q
Pooters
A
- containers with a straw device
- used to suck in small animals so they can be identified and counted
7
Q
Pitfall traps
A
- small containers buried in ground
- collect animals that fall into them
- can then count animals in area
8
Q
Capture recapture count
A
- capture a sample of organisms in an area (first sample), count, mark, release them
- recapture and count a second sample of organisms in the same area as the first sample
- count the total number of recaptured (previously marked) organisms in second sample
9
Q
Equation to measure population size
A
(number in 1st sample x number is 2nd sample) / number in 2nd sample previously marked
10
Q
Factors for accurate sampling
A
- big enough sample
- reliable
- fair
11
Q
Factors biologists assume don’t happen during ‘capture recapture count’
A
- no death
- no immigration
- no emigration
- no birth
12
Q
Ways of ensuring capture recapture count is fair
A
- the sampling method used is the same each time
- the marking of organisms does not affect their survival
