#3 Investigating Populations - Sampling

Question 1

What is sampling used for?

Answer 1

to measure biodiversity of a habitat or the abundance of species

Question 2

What is it impossible to count?

Answer 2

all of the organisms of a species

Question 3

What do the samples need to be representative of?

Answer 3

the whole habitat / ecosystem (repeats)

Question 4

What do you use sample data for?

Answer 4

to extrapolate to estimate the total number of individuals in the habitat / ecosystem

Question 5

Random Sampling - What do you avoid?

Answer 5

avoid bias

Question 6

Random Sampling - What do you divide sampling area into?

Answer 6

a grid

Question 7

Random Sampling - What do you use a random number generator for?

Answer 7

to pick coordinates

Question 8

Plants -

Mobile Animals -

Flying insects

Answer 8

Plants - Quadrats

Mobile animals - traps

Flying insects - sweep nets

Question 9

Do the sample size need to be small or large?

Answer 9

large - and need lots of repeats

Question 10

What should you sample at?

Answer 10

different times of day / year, weather conditions

Question 11

What do you standardise?

Answer 11

sampling methods

Question 12

What do you avoid capturing?

Answer 12

the same individuals twice

Question 13

What do you calculate?

Answer 13

the mean

Question 14

What do you use?

Answer 14

a statistical test

Question 15

In systematic sampling, what are samples taken at?

Answer 15

fixed intervals

Question 16

In systematic sampling, what does it measure?

Answer 16

a change in the enviroment

Question 17

In opportunistic sampling, who are sample sites chosen by?

Answer 17

investigator - samples will be biased

it is also easy and fast to do

Question 18

Stratified sampling - What is the survey area divided into?

Answer 18

groups

Question 19

Stratified sampling - How is each area surveyed?

Answer 19

separately e.g. 5% pond, 20% wood land, etc.

in proportion to its coverage of total area