21 The impact of population increase

Question 1

give three factors that affect human population growth

Answer 1

birth rate (BR)

death rate (DR)

food production

medical technology

disease control

Question 2

what are the features of stage 1 of human population growth?

Answer 2

high fluctuating BR/DR

small stable population

Question 3

what are the features of stage 2 of human population growth?

Answer 3

early expansion - DR starts to decrease

introduction of medicines ∴ DR decreases (fewer children)

Question 4

what are the features of stage 3 of human population growth?

Answer 4

late expansion - BR starts to decrease

children become an economic disadvantage

Question 5

what are the features of stage 4 of human population growth?

Answer 5

low fluctuating BR/DR

large stable population

Question 6

give three examples of the effect of human population growth on abiotic factors

Answer 6

fewer resources

reduced living space

reduced farming space

salinisation

incr. greenhouse gas production

draining aquatic ecosystems

Question 7

give three examples of the effect of human population growth on biotic factors

Answer 7

incr. spread of disease

pollution of air and water

deforestation

incr. global temperature
decr. nutrient content of soil

agricultural monoculture

Question 8

what is the definition of food security?

Answer 8

a stable food supply

Question 9

what are the seven factors that must be considered of a food supply?

Answer 9

sustainability

availability

access

affordability

nutrition

quality

safety

(Sally Always Ate Avocados; Never Question Sally)

Question 10

give three factors that put food security at risk

Answer 10

incr. population

changing diets

reduced arable land

transport costs

climate change

Question 11

what would be the risks if we grew all our own food in the UK?

Answer 11

poor harvests

new diseases

specific pest issue

Question 12

what is the aim of the food and agriculture organisation (FAO)?

Answer 12

to reduce hunger,

poverty,

food insecurity

and malnutrition

Question 13

what is the aim of the food chain crisis (FCC)?

Answer 13

to tackle threats to the food chain

Question 14

what is the aim of the emergency prevention system (EMPRES)?

Answer 14

promoting research and assessment of potential crises in the food chain

coordinating warnings at beginning of outbreaks

containment and control

Question 15

what is sampling?

Answer 15

obtaining an estimate of the variety and quantity of organisms in an ecosystem

Question 16

what are the advantages and disadvantages of large sample sizes?

Answer 16

+ increases validity

• requires time, energy and money

Question 17

how is a random sample performed?

Answer 17

use a quadrat to measure % cover of an area

use randomly generated coordinates to identify the location

use a key to identify species

Question 18

what are the disadvantages of random sampling?

Answer 18

can produce unrepresentative picture

can miss some species if only found in specific parts

Question 19

what is stratified sampling?

Answer 19

representative random sampling within sub regions

Question 20

how is a transect used?

Answer 20

to identify correlations between abiotic variables and distribution of organisms

Question 21

what is species richness?

Answer 21

the total number of species in an area

Question 22

what is species evenness?

Answer 22

how evenly a species is represented in an area