distrubution of organisms

Question 1

Describe a biotic factor, giving examples.

Answer 1

Biotic factors are living factors which can affect biodiversity in an area. Examples of biotic factors are:

Competition for resources
Disease
Grazing
Predation

Question 2

Describe an antibiotic factor, giving examples.

Answer 2

Abiotic factors are non-living factors which can affect biodiversity in an area. Examples of abiotic factors are:

Light Intensity
Soil moisture
pH
Temperature

Question 3

Identify a source of error and limitation regarding the use of the light meter

Answer 3

Accidental covering of the probe, must be taken at the same time of day.

Question 4

Identify a source of error and limitation regarding the use of the moisture meter.

Answer 4

Must be placed at the same depth in the ground at each site and wiped clean between readings

Question 5

Identify a source of error and limitation regarding the use of the pH meter.

Answer 5

pH probe must be placed at the same depth and wiped clean between readings.

Question 6

Identify a source of error and limitation regarding the use of the thermometer.

Answer 6

Thermometer must be held in the same position/depth at every sample point. Time must be allowed for the reading to be taken.

Question 7

Name and describe a technique used to sample ground dwelling invertebrates

Answer 7

A pitfall trap is used to measure small invertebrates that live on the ground.

Question 8

Describe a limitation/source of error when using a pitfall trap. Say how would you overcome the error.

Answer 8

Not enough samples taken.
Set up more traps within the sample site

Question 9

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Describe a quadrat and the organisms that it is used to sample.

Answer 9

A quadrat is used to sample plants and animals that don’t move

Question 10

Describe a limitation/source of error when using a quadrat. Say how would you overcome this error.

Answer 10

Not enough samples taken within the sample site.

Question 11

What are the effects of biotic and abiotic factors have on biodiversity and the distribution of organisms?

Answer 11

Both biotic and abiotic factors can increase or decrease biodiversity in an area and affect the distribution of organisms.

Question 12

How do humans influence biodiversity and distribution of organisms?

Answer 12

Air pollution
Water pollution
Habitat destruction by deforestation
Desertification
Overfishing

Question 13

Describe an indicator species

Answer 13

An indicator species by their presence or absence will indicate environmental quality/levels of pollution in an area.