practical skills

Question 1

why should you have a large sample size?

Answer 1

increased reliability of data + more representative

Question 2

when should you use systematic sampling?

Answer 2

when about distance, samples are taken at (named) regular intervals

Question 3

when should random sampling be used?

Answer 3

when the area is uniform, used for studying distribution (of plants or animals that don’t move much)

Question 4

when should a transect be used?

Answer 4

if there is an environmental gradient

Question 5

what’s the difference between a belt vs. line transect?

Answer 5

belt = with quadrat along the transect
- gives info on abundance but may be potentially more damaging
line = no quadrat, just whatever’s touching the transect directly
- quick + easy

Question 6

why use random sampling?

Answer 6

-eliminates bias - data is representative
-allows use of stats test

Question 7

what are some considerations when using quadrats?

Answer 7

• the size of quadrat (based of size of species + distribution)
  -number of samples taken in an area - [min 10, until running mean levels out]
  -position of each quadrat - random no. generator + coordinates
  ^(calc. = Rnd#1-10) eg. 10Rnd#
  -type of quadrat eg. gridded

Question 8

how many repeats should one do?

Answer 8

minimum 10 (more = better)
- large enough number to ensure reliable data
- enough to carry out a stats test
-until running mean levels off with little fluctuations
^any more = waste of time, not efficent

Question 9

what’s the calculation for: population density

Answer 9

population density = number/area
(individuals m^2-1) (m^2)

Question 10

how do you work out % cover?

Answer 10

estimate of area covered in quadrat

Question 11

which area is more species diverse: index of 1.5 or 2.7

Answer 11

2.7! - higher no.= more diverse

Question 12

when do you use %cover?

Answer 12

if species abundant is difficult to count individuals eg. moss
+ data collected very quickly

Question 13

why calculate frequency?

Answer 13

gives an idea of what species are present eg. is 13/30 quadrats have species.. frequency =43%
dis = no info on pop. density

Question 14

what is a representative sample?

Answer 14

a sample/ small portion of the total that accurately reflects the entire population

Question 15

whats the ideal sample size?

Answer 15

samples until the running mean levels out

Question 16

how does one ensure their results are representative?

Answer 16

standardize!!!!!!!
eg. what, where, when, how, how many etc..
^^keep all the same BUT the IV
+large enough sample size

Question 17

describe the steps of mark recapture release

Answer 17

-capture no. of animals
-carefully mark them
-release them + allow time to re-integrate with pop.
-collect 2nd sample
-count + record no. of marked + unmarked
-use Lincoln index to estimate pop. size

Question 18

what is Lincoln index + what is it and MRR used for?

Answer 18

estimating population size:

total pop. = number or organisms in sample 1 x
. number of organisms in sample 2
. —————————————————
. number of marked organism in sample 2

Question 19

what does MRR assume?

Answer 19

• no natural population change ie. no deaths, births, migration etc..
  -there is enough time/ the population is fully re-integrated/mixed
  -all organisms have an equal likelihood of getting caught
  -the marks are don’t rub off/ the individuals are identifiable
  -the sample size is large enough

Question 20

how can data be made scientifically valid?

Answer 20

-do a large amount of samples
- collect samples at different times of day, season, and year etc..

Question 21

what should you do if the question says “use the information”

Answer 21

quote data!!!!

Question 22

what does -1 at the end of a unit mean?

Answer 22

per
ie. LU-1 = per livestock unit

Question 23

what should be done if you don’t know the calculations for a maths question

Answer 23

multiply or divide and then pick the most reasonable answer

Question 24

what is the structure for a practical question

Answer 24

technique, representative and data collected

Question 25

what is meant by 'representative' in the structure of a practical question answer

Answer 25

- location and timing - systematic or random (always say one!!) - number of repeats (for reliable data +/ carry out a stat test) - standardisation - sample size

Question 26

name three factors for areas that should be standardised if they are not being investigated

Answer 26

climate, temperature, vegetation, time of year/ season etc..

Question 27

name 10 lowkey sampling techniques

Answer 27

- kick sampling - surber samplers - suction samplers/ pooters - pitfall traps - sweep nets - beating trays - transect lines - quadrats - light traps - tullgren funnel - collection of earthworms - indirect evidence

Question 28

why use a beating tray

Answer 28

to sample populations of invertebrates attached to overhanging branches of shrubs or trees

Question 29

describe how to use beating trays

Answer 29

a tray/ sheet is placed under a branch, the branch is hit repeatedly with a stick, invertebrates are dislodged and fall off

Question 30

what are the limitations of beating trays

Answer 30

- hard to standardise force of branched striking - some species are more easily dislodged than others - not all branches can be reached

Question 31

name ways to standardise the use of beating trays

Answer 31

- the size of the tray - the number of hits - weather conditions - time of day/ year

Question 32

describe how to use transect Lines

Answer 32

-line placed along an environmental gradient - samples taken at points along the line 9

Question 33

name a limitation of transect lines

Answer 33

only representative data if transect is typical of area of study

Question 34

name ways to standardise transect Lines

Answer 34

-distance between points - weather conditions - time of day/ year

Question 35

name an advantage of quadrats

Answer 35

can calculate frequency and percentage cover

Question 36

name a limitation of quadrats

Answer 36

-May involve selective judgement eg. percentage cover -frame may flatten/ damage vegetation

Question 37

why use light traps

Answer 37

to sample populations of insects attracted to bright lights - usually night flying insects

Question 38

describe how to use a light trap

Answer 38

light trap is left overnight, bright light attracts flying insects into trap

Question 39

name a limitation of light traps

Answer 39

light may be more attractive to certain species

Question 40

name ways to standardise light traps

Answer 40

- wavelength of light - power / brightness of light - size and type of trap - time left outside - weather conditions - time of year/ ear season

Question 41

why use a tullgren funnel

Answer 41

to sample populations of mobile invertebrates in soil/ Leaf litter

Question 42

describe how to use a tullgren funnel

Answer 42

soil/ Leaf litter placed on mesh tray with light above, invertebrates are repelled by light and move downwards into the pot

Question 43

name some limitations of tullgren funnels

Answer 43

-not all species are repelled by light/ heat - some species are too large to pass through the mesh - organisms may die due to heating

Question 44

why use photographic surveys

Answer 44

to sample large organisms or those that tend to be rarer with low population densities

Question 45

describe the use of photographic surveys

Answer 45

motion sensitive cameras are used to estimate abundance or aerial photographic surveys if there is open land

Question 46

name some limitations of using photographic surveys

Answer 46

- some species are more likely to be spotted - some individuals may trigger the camera multiple times

Question 47

describe sampling by indirect methods for sampling

Answer 47

markers used to identify individuals that are exclusive or too rare to be seen normally - markers can range from: - droppings - nests/ Burrows - footprints/ tracks - territorial marks -(sometimes DNA analysis) with these, population abundance can be determined

Question 48

name a limitation of using indirect evidence for sampling

Answer 48

-may require technology to analyse and determine different individuals - organisms are not actually seen - only impressions and opinions, not hard evidence

Question 49

why use the collection of earthworms

Answer 49

to sample earthworm population in soil

Question 50

describe using collection of earthworms

Answer 50

-area of soil is flooded with irritant solution (eg. dilute acid, mustard water etc..) -area is marked out with quadrat - soil is observed for set time - worms may appear and be collected

Question 51

some limitations of using the collection of earthworms technique

Answer 51

- differences in soil will influence results - some worms may escape by moving sideways

Question 52

name ways to standardise the collection of earthworms

Answer 52

- time left waiting - volume of solution - size of quadrat/ area - weather conditions (ie. rainfall) - time of day/ year

Question 53

name six specialised sampling techniques

Answer 53

- tagging - auditory monitoring - photographing - Trackers - satellite sensing - DNA databases - indirect evidence

Question 54

name an advantage of using indirect methods for sampling

Answer 54

easy to administer

Question 55

why use satellite sensing

Answer 55

- for seeing what animals are present and where -weather monitoring - infrared admitted - shows vegetation density and temperature - reflected visible light - for creating maps and environmental changes

Question 56

name advantages of satellite sensing

Answer 56

large amounts of data can see animal movement and activity

Question 57

name a disadvantage of satellite sensing

Answer 57

only shows one point at a time

Question 58

why use DNA databases

Answer 58

to identify individuals, Gene pools, and other genetic relationships ( genetic diversity) eg.eDNA shed in water

Question 59

what is eDNA

Answer 59

environmental DNA

Question 60

name the advantages of using DNA databases

Answer 60

- very specific - DNA can be compared, can track back to find it origin

Question 61

name disadvantages for using DNA databases

Answer 61

- have to get close up to the animal to extract DNA - DNA degrades quickly (in warm conditions)

Question 62

why use tagging

Answer 62

to identify already caught organisms for information on movement and life span eg. rings on bird legs

Question 63

name an advantage of tagging

Answer 63

clear to tell exactly which animal

Question 64

name a disadvantage of tiger

Answer 64

- can be irritating to the animal - could be removed

Question 65

why use auditory monitoring

Answer 65

species that cannot be seen can be found by the sounds they produce eg. bats

Question 66

name an advantage of auditory monitoring

Answer 66

information can be gathered with interfering

Question 67

name a disadvantage of auditory monitoring

Answer 67

the animal is not actually seen

Question 68

why use photographing

Answer 68

using a range of technologies to monitor the presence and activity of individuals day and night/ behavioural habits eg. camera traps, radio, GPS, acoustic transmitters

Question 69

name an advantage of photographing

Answer 69

can be set up and left

Question 70

name a disadvantage of photographing

Answer 70

only sees one moment at a time

Question 71

why use trackers

Answer 71

trackers place on animals to track movements

Question 72

name an advantage of trackers

Answer 72

easy to gather data can be reused

Question 73

name a disadvantage of tractors

Answer 73

battery can run out can irritate the animal

Question 74

what does "used in preference" mean

Answer 74

why better than _______

Question 75

what is the structure of a 9 marker

Answer 75

3-4: point - detail/ explanation - examples eg. technology - data provided - conservation value

Question 76

what is needed for a 9 marker

Answer 76

B- breath R- relevance E- examples A- accuracy K- key terms

Question 77

what is Simpson's diversity index

Answer 77

N(N-1) ---------- (sum of) n(n-1)

Question 78

what does N mean in Simpson's diversity index

Answer 78

total number of all species

Question 79

what does n mean in Simpson's diversity index

Answer 79

total number of each species