21) The impact of population increase

Question 1

Name 4 factors which affect the size of a population

Answer 1

birth rate
death rate
immigration
emigration

Question 2

Name the 3 phases of a typical birth + death rate - time graph

Answer 2

lag phase
exponential phase
stationary phase

Question 3

State 3 factors affecting birth rate and death rate

Answer 3

food production
advances in medical technology
disease control

Question 4

Explain how food production can affect birth rate and death rate

Answer 4

intensive farming - increasingly secure food supply / excess food production
lack of resources - malnutrition

Question 5

Explain how advances in medical technology can affect birth rate and death rate

Answer 5

vaccinations, antibiotics and fertility treatments - increase life expectancy and fertility in economically developed nations
inequalities in availability - high birth and death rates (birth control is less common and economic prosperity depends on the number of children able to support the family by earning money)

Question 6

Explain how disease control can affect birth rate and death rate

Answer 6

disease vulnerability is a density-dependent factor
diseases can be transmitted more easily in large populations
HIV + tuberculosis -> high death rates in less economically developed nations
diarrhoea due to lack of water treatment and sewage disposal

Question 7

State 3 abiotic factors of ecosystems which are impacted by the rise in human populations

Answer 7

water quality
soils
climate

Question 8

Explain how water quality is impacted by the rise in human populations

Answer 8

eutrophication by fertilisers (pollution, decreasing population of species)
rivers + lakes drained due to increased demand for water and irrigation projects (ecosystem collapse)

Question 9

Explain how soils are impacted by the rise in human populations

Answer 9

salinisation (increased salt content in soils) due to irrigation - widespread soil degradation and decreased agricultural potential

Question 10

Explain how climate is impacted by the rise in human populations

Answer 10

emissions of greenhouse gases -> global climate change and increase in mean temperature

Question 11

Explain how biodiversity is impacted by the rise in human populations

Answer 11

direct damage to organisms:

• deforestation of rainforests (habitats)
• agricultural monocultures (reduce plant diversity and removes food sources)
• pesticides (kill un-targeted organisms e.g. bees)

Question 12

Why is species diversity important? 3 reasons

Answer 12

high genetic diversity - increases chance of species adapting to future environmental change
extinct species may have possessed genes useful to medical research / agriculture
aesthetic aspect

Question 13

Give the equation for Simpson’s diversity index (D)

Answer 13

1 - [∑(n/N)^2]
n = number of individuals of a particular species
N = total number of all individuals of all species

Question 14

What value is Simpson’s diversity index (D)?

Answer 14

a value between 1 and 0

Question 15

What does a high value for Simpson’s diversity index (D) show?

Answer 15

high biodiversity

Question 16

What does a low value for Simpson’s diversity index (D) show?

Answer 16

ecosystem dominated by a few species and is unstable

Question 17

Define food security

Answer 17

the ability of a population to obtain sufficient amounts of safe and nutritious food

Question 18

Name 3 food system challenges

Answer 18

food safety (danger of hygiene standards dropping due to increasingly intensive production methods)
food crime / fraud (food sold with the intention of deceiving the consumer)
consumer trust

Question 19

What is the role of the united nations food and agriculture organisation (FAO)?

Answer 19

in charge of protecting global food security with aims of reducing hunger, poverty, food insecurity and malnutrition; to ensure natural resources are managed sustainably

Question 20

What is the role of the food chain crisis management framework (FCC)?

Answer 20

deals with food safety by tackling threats to the human food chain e.g. diseases and pests

Question 21

What is the role of the emergency prevention system (EMPRES)?

Answer 21

promotes research and assessment of potential crises in the food chain, coordinating early warnings at the beginning of outbreaks and promoting containment and control during outbreaks

Question 22

Outline the main features of intensive farming

Answer 22

use of pesticides
confinement of livestock to reduce energy lost
high use of fertilisers

Question 23

Suggest two disadvantages of intensive farming

Answer 23

reduction in biodiversity

disease is more likely to spread

Question 24

Give an economic reason for maintaining biodiversity other than increasing the chance of species adapting to future environmental change and production of medicines

Answer 24

generates jobs