Distribution of organisms

Question 1

Identify biotic and abiotic factors

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

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 2

Describe how abiotic factors can be measured

Answer 2

Scientists use equipment to measure abiotic factors within a particular environment. These are:

light intensity - light
meter/probe

soil moisture - moisture meter

pH - pH meter/probe

temperature - thermometer

Question 3

Describe a technique to sample plants, stating limitations and possible source of error

Answer 3

Limitations are:

not enough samples taken within the sample site

deliberately ‘choosing’ good spots

Question 4

Describe the effects of biotic and abiotic factors on biodiversity and the distribution of organisms

Answer 4

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

Question 5

Describe some human influences and describe the effects on biodiversity

Answer 5

air pollution

water pollution

habitat destruction by

deforestation

desertification

overfishing

Question 6

Describe an indicator species

Answer 6

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