Key Area 1 - Biodiversity and Interdependence

Question 1

What is a habitat?

Answer 1

A habitat is the place where an organism lives. Examples: Woodland, meadow, pond.

Question 2

What is a population?

Answer 2

A population is the number of organisms of one species in an ecosystem. Example: the number of squirrels in Lochend Woods.

Question 3

What is a community?

Answer 3

A community includes all the organisms (all populations) that live together in an ecosystem.

Question 4

What is an ecosystem?

Answer 4

An ecosystem is a natural biological unit made up of living and non-living parts. It includes the habitat plus the community that lives there.

Question 5

What is an adaptation?

Answer 5

An adaptation is any feature that makes an organism well suited to living in its environment.

Question 6

What are abiotic factors?

Answer 6

Abiotic factors are non-living features of an ecosystem.

Question 7

Give 4 abiotic factors that affect populations in aquatic ecosystems.

Answer 7

Abiotic factors that affect aquatic ecosystems include water flow rate, oxygen concentration, water pH and water temperature.

Question 8

Give 7 abiotic factors that affect populations in terrestrial ecosystems.

Answer 8

Abiotic factors that affect terrestrial ecosystems include temperature, light intensity, soil moisture, soil pH, wind velocity, wind direction and precipitation.

Question 9

What would you use to measure temperature?

Answer 9

Thermometer

Question 10

What would you use to measure light intensity?

Answer 10

Light meter

Question 11

Describe 2 ways you could measure soil moisture.

Answer 11

Moisture meter.

Oven drying a sample of the soil to calculate the % water

Question 12

Describe 2 ways you could measure soil or water pH.

Answer 12

pH meter

Universal indicator. For soil pH the sample would need to be mixed with water and then filtered.

Question 13

What equipment would you use to measure wind speed?

Answer 13

Anemometer

Question 14

What piece of equipment would you use to measure wind direction?

Answer 14

Weather vane.

Question 15

What piece of equipment is used to measure precipitation?

Answer 15

Rain gauge

Question 16

Describe 2 ways to measure water flow rate.

Answer 16

Use a flow meter

Float method - drop a floating object and time how long it takes to travel a measured distance.

Question 17

What piece of equipment is used to measure oxygen concentration?

Answer 17

Oxygen meter

Question 18

How can an experiment or the estimate from a sampling technique be made more reliable?

Answer 18

To improve the reliability, repeat measurements should be taken.

Question 19

How can the accuracy of a measurement be improved?

Answer 19

Accuracy is improved by having properly calibrated equipment that is used appropriately (for example probes should be cleaned and dried between uses). It can also be improved by using equipment that can measure more accurately (to more decimal places)

Question 20

What does the term precise mean when discussing a set of results?

Answer 20

Results are precise if the values measured are close to each other and close to the actual value. For example pH readings of 7.6, 7.6, 7.5 and 7.7 indicate higher precision than readings of 7.2, 7.5, 7.7 and 8.0. Precise results are reliable and accurate.

Question 21

List 6 sampling techniques used to determine the presence or abundance of a species in an area.

Answer 21

Sampling techniques include use of quadrats, dip nets, sweep nets, pitfall traps, mammal traps and camera traps.

Question 22

Sampling is an example of a quantitative technique. What is a quantitative technique?

Answer 22

Sampling is a quantitative technique. Quantitative techniques provide information about the frequency (how many there are) and distribution (where they are) of organisms.

Question 23

What are quadrats used for?

Answer 23

Quadrats are used to sample plans or slow (or non) moving animal species. Results are used to calculate the abundance of the species investigated.

Question 24

Describe how you could use the results of quadrat sampling to estimate the total population in an area.

Answer 24

Once you have used your quadrat to find the average number of plants per m2 this can be multiplied by the number of m2 in the whole area to calculate an estimated population size for that area.

Total population = population size/m2 x total area (in m2)

Question 25

In addition to repeating trials, how else can the reliability of the estimate from a sampling method be improved?

Answer 25

Reliability of the estimated abundance of a species in an area using sampling techniques can be improved by repeated trials or increasing the sample size.

Question 26

What does random sampling involve?

Answer 26

Random sampling involves every individual in a population having an equal chance of being selected.

Question 27

How can random sampling be carried out when using quadrats?

Answer 27

When using quadrats this can be achieved by using a random number generator to select coordinates in a grid.

Question 28

Why do we use random sampling?

Answer 28

To reduce bias.

Question 29

List 3 types of random sampling.

Answer 29

There are different types of random sampling: simple, stratified and systematic.

Question 30

Give an example of bias when using a quadrat.

Answer 30

Bias is introduced when sampling is not random. An example would be throwing a quadrat towards a patch of daisies instead of randomly throwing it.

Question 31

Why is the accurate identification of species important when sampling?

Answer 31

Accurate identification of species is important when sampling to improve the accuracy of the calculated abundance.

Question 32

What are transect studies used for?

Answer 32

A transect study makes use of quadrats to study the change in abundance of species when abiotic factors are changing.

Question 33

What equipment is used to sample aquatic invertebrates?

Answer 33

Dip nets can be used to sample aquatic invertebrates in rock pools, ponds or river shallows.

Question 34

What equipment is used to sample invertebrates in long grasses or hedges?

Answer 34

Sweep nets are used to sample invertebrates in long grasses or hedges.

Question 35

What are pitfall traps used for?

Answer 35

Pitfall traps are used to sample invertebrate populations on the ground.

Question 36

List 3 other methods of sampling organisms that are harder to catch so population sizes can be monitored.

Answer 36

Camera traps, footprint traps and fur tubes can be used to monitor populations.

Question 37

What is the capture-mark-recapture technique used for?

Answer 37

Capture - Mark - Recapture is a technique used to estimate the population size of animals and invertebrates.

Question 38

How can invertebrates be marked for capture-mark-recapture?

Answer 38

Invertebrates can be marked with a coloured spot.

Question 39

How can small mammals be marked for capture-mark-recapture?

Answer 39

Mammals can be marked by shaving fur, snipping a notch in the ear, tags or leg bands.

Question 40

What is the formula used to estimate a population size using capture-mark-recapture?

Answer 40

Skill: To estimate the population size from a Capture-Mark-Recapture exercise the following equation can be used (this will be given to you on an exam question).

Estimated population size = 1st sample x 2nd sample

2nd sample previously marked

Question 41

Why do we measure abiotic factors in an ecosystem?

Answer 41

Abiotic factors will have an effect on the distribution of organisms. For example light intensity, soil moisture and soil pH will have an effect on the plant species which will be found in an area.

Question 42

What tool is used to identify organisms?

Answer 42

Paired statement keys are used to identify organisms. Skill: You need to be able to use and construct paired statement keys.

Question 43

How do you calculate the lowest whole number ratio?

Answer 43

Data for abundance can be expressed as a ratio. If there were 100 rabbits on the playing field and 20 foxes you could be asked for the ration of rabbits to foxes.

This would be written as

Rabbits : Foxes

100 : 20

Divide by the lowest number to get the lowest whole number ratio

100: 20

20 : 20

5:1