Populations and Sustainability

Question 1

what is population

Answer 1

• group of organisms of the same species that live in the same habitat
• can interbreed and reproduce fertile offspring

Question 2

what are factors that affect birth rate

Answer 2

• economic conditions
• cultural and religious backgrounds
• social pressures and conditions
• birth control
• political factors

Question 3

what are factors that affect death rate

Answer 3

• age profile - elderly population
• life expectancy
• food supply
• safe drinking water
• sanitation
• medical care
• natural disasters
• war

Question 4

what is carrying capacity

Answer 4

• maximum population size that can be maintained in a particular habitat

Question 5

what are the features of a population growth curve

Answer 5

Lag phase
- low birth rate and low death rate
-birth rate is greater than death rate
- small number of individuals reproduce

Log phase
- increasing number of individuals
- reproduce exponentially

• population has reached its carrying capacity
• population declines until it remains stable
• birth rate = death rate

Question 6

what are k-strategists

Answer 6

• limiting factors exert more of an effect as the population grows closer to carrying capacity
• gradually levels out
• low reproductive rate, slow development, long life span, large body mass

Question 7

what are r-strategists

Answer 7

• population size rapidly increases and passes carrying capacity
• not enough resources to survive or reproduce
• build up of waste products
• high reproductive rate, fast development, short life span, small body mass

Question 8

what are limiting abiotic factors

Answer 8

• light, water, oxygen, humidity, toxic waste
• each species has a different optimum temperature
• Bears hibernate in the winter to increase their survival by conserving energy
• bacteria grow in warm conditions
• Algae needs favourable conditions such as nutrients and lights

Question 9

what are limiting biotic factors

Answer 9

• food, competition, predators, disease
• some bacteria produce antibiotics

Question 10

what is immigration

Answer 10

• movement of individuals into an area

Question 11

what is emigration

Answer 11

• movement of individuals away from an area

Question 12

what are density independent factors

Answer 12

• has an affect on the whole population
• natural disasters

Question 13

what is interspecific competition

Answer 13

• competition between species
• as one population size grows the other shrinks
• individuals who are different species compete for resources

Question 14

what is intraspecific competition

Answer 14

• competition with a species
• individuals who are the same species compete for resources
• availability of resources determine population size

Question 15

how has interspecific competition been investigated

Answer 15

• two species of paramecium are grown
• when grown together there is a greater competition for food

Question 16

what is an example of predator-prey relationships

Answer 16

• increase in rabbits means the population of the foxes grow = more food = survive = reproduce
• high number in foxes there is a decline in the rabbit population
• less rabbits = less foxes
• less foxes = less rabbits eaten

Question 17

what is conservation

Answer 17

• maintaining biodiversity through human action or management
• maintain species diversity/genetic diversity
• sustainable development

Question 18

what is preservation

Answer 18

• restricting or banning human interference

Question 19

what is the importance of conservation

Answer 19

Economic
- resources that humans need to survive and provide income

Social
- natural beauty, relaxation, exercise

Ethical
- all organisms have the right to exist and have a role in their ecosystem
- don’t have the right to decide which organisms live/die
- moral obligation to future generations to conserve variety of existing ecosystems

Question 20

what are the aims of sustainability

Answer 20

• preserve the environment
• ensures resources are available for future generations
• allows humans in all societies to live comfortably
• enables LEDCs to develop through exploiting natural resources
• create a more even balance in the consumption of resources between countries

Question 21

what is the case study of sustainable development

Answer 21

Andrex
- products are 100% biodegradable and recyclable
- manufacturing - 5% less water used and 0% waste

Question 22

what is involved in small scale timber production

Answer 22

Coppicing
- tree trunk cut close to the ground
- new shoots grow from the cut surface
- cut and more grow again

Pollarding
- trunk cut higher up so animals cannot eat new shoots

Question 23

what is involved in large scale timber production

Answer 23

Felling
- felled trees are destroyed and won’t regrow

Question 24

what is sustainable timber production

Answer 24

• selective cutting - remove largest trees
• replace trees - replant
• plant trees an optimal distance apart to reduce competition
• minimise pests and pathogens

Question 25

what are fishing quotas

Answer 25

• limits the amount of fish allowed to catch
• study different species and how big their populations are
• can work how many fish it is safe to take without reducing the population

Question 26

conservation and preservation in the Terai Arc

Answer 26

• area of forest and grasslands between Nepal and India
• 7 million live in the area and are dependent on resources
• areas of the forest are being destroyed to make room for houses
• humans and animals in closer contact and increases livestock
• WWF has helped local people balance their needs with conserving forests
• farmers encouraged to plant mint hedges around crops to keep animals away

Question 27

conservation and preservation in the Maasai Mara

Answer 27

• national reserve in Kenya of large grassland
• people earn a living by raising livestock such as cattle
• overgrazing livestock can destroy grassland
• farm in a sustainable way and make money through ecotourism

Question 28

conservation and preservation in UK Peat Bogs

Answer 28

• areas of wet peat that store water and carbon dioxide
• use peat bogs to graze sheep and deer
• overgrazing = loss of moss species, soil compaction
• farmers given money to carry out sustainable measures

Question 29

human activities on the Galapagos islands

Answer 29

• non-native animals introduced by humans eat some native species . Goats have eaten much of the plant life
• non-native plants also introduced
• eradication programmes removed wild goats
• humans expected to follow rules

Question 30

human activities in Antarctica

Answer 30

• visitors have caused pollution by dumping sewage into the sea
• hunting, whaling and fishing have reduced the population
• all waste must be taken away by ships and disposed of in other countries
• ships that use thick oil as a fuel are now banned from Antarctic waters
• hunting and whaling have been banned

Question 31

human activities in the lake district and Snowdonia national park

Answer 31

• erosion of footpaths and loss of soil from hillsides
• soil ends up in lakes and can disturb the pH of the water
• vegetation can be destroyed
• conservation charities carry out regular repairs and maintenance work
• encourage regrowth of damaged vegetation