6.3.2: Populations and sustainability

Question 1

Give 3 factors that determine the size of a population

Answer 1

• Natural disasters
• Availability of food
• Cultural or religious beliefs

Question 2

Define limiting factors

Answer 2

Things that prevent further growth of a population and can lead to decline

Question 3

Give 3 limiting factors which can determine the carrying capacity of an environment

Answer 3

• Competition for resources
• Disease
• Build up of the toxic by products of metabolism

Question 4

Define abiotic factor and give 3 examples

Answer 4

Non-living component of an environment: temperature, light, pH

Question 5

Define biotic factor and give 3 examples

Answer 5

Living component of an environment: predators, disease, competition

Question 6

What is immigration ?

Answer 6

Movement of organisms into an area which increases population size

Question 7

What is emigration ?

Answer 7

Movement of organisms away from an area which decreases population size

Question 8

Define density independent factor

Answer 8

Factors which have an effect on the whole population regardless of its size

Question 9

Give an example of a density independent factor

Answer 9

Natural disasters

Question 10

Define predation

Answer 10

Biotic factor where one organism is consumed by another as a food source

Question 11

What is interspecific competition ?

Answer 11

Competition between members of different species

Question 12

What is interspecific competition usually caused by and give the sequence of events

Answer 12

Competition over a resource such as food which leads to a reduction in food available to both species meaning less energy for growth and reproduction and a overall smaller population

Question 13

What is the competitive exclusion principle ?

Answer 13

One species can eliminate the other by out competing it for resources as it is better adapted and can obtain the resource more effectively

Question 14

Give an example of interspecific competition

Answer 14

Red and grey squirrels in the UK as the grey squirrels ate a larger range of food and were larger so could store more fat and survive longer in harsh months

Question 15

What is intraspecific competition ?

Answer 15

Competition between members of the same species

Question 16

What is a feature of intraspecific competition ?

Answer 16

It is density dependent as an increase in density of a population leads to an increase in intraspecific competition

Question 17

What are predator-prey relationships an example of ?

Answer 17

Interspecific competition

Question 18

Describe a predator-prey relationship

Answer 18

• Increase in prey population increases food for predators so more survive and reproduce which increases the predator population
• More predators means more prey are eaten which decreases the prey population as death rate is higher than birth rate
• Reduced prey population can’t support large predator population so intraspecific competition increases which decreases predator population
• Less prey eaten means more survive and reproduce which increases the prey population
• CYCLE REPEATS

Question 19

Define conservation

Answer 19

The maintenance of biodiversity through human action or management

Question 20

What are 3 features of conservation ?

Answer 20

• Maintaining diversity between species
• Maintaining genetic diversity within a species
• Maintenance of habitats

Question 21

What are the 3 reasons for conservation ? explain them

Answer 21

• Economic ( provide resources that humans rely on for an income e.g. rainforest species provide medicinal drugs
• Social ( people enjoy the natural beauty of ecosystems for exercises to boost health)
• Ethical ( people believe we shouldn’t have the right to decide which organisms survive and we have a moral responsibility for future generations to conserve natural ecosystems)

Question 22

Define preservation

Answer 22

The protection of an area bu restricting or banning human interference so that the ecosystem is kept in its original state

Question 23

What are the 3 types of sensitive resources which could be destroyed by disturbances ?

Answer 23

Ecologically
Paleontologically
Archaeologically

Question 24

How can preservation be carried out ?

Answer 24

Visitation to areas is prohibited except those who manage and monitor it meaning the integrity of the ecosystem is guaranteed but people can’t enjoy it

Question 25

Give 2 examples of preservation

Answer 25

Nature reserves or marine conservation zones

Question 26

Explain how timber production in temperate woodlands can be sustainably managed

Answer 26

Trees cleared in strips as woodlands grow back quicker in small areas where there is existing woodland and relationships. Cleared strips aren’t exposed to prevent soil erosion so more trees can grow back

Question 27

Explain what coppicing is and how it can allow timber production in temperate woodlands to be managed sustainably

Answer 27

Coppicing is cutting down trees so they can grow back
- Native species are planted as they have long established interactions with biodiversity
- Trees planted next to posts for support and with plastic tubes so they aren’t eaten so can survive and mature
- Trees aren’t planted close to eachother so they aren’t competing for space and resources and are more likely to survive

Question 28

Give 2 examples where there is managed conflict between conservation and human needs

Answer 28

• Conservation trusts work with Massai Mara people to make money from ecotourism and not overgrazing and farming
• Government pays farmers to use peat bogs sustainably

Question 29

What are the 2 ways how fishing is sustainably managed ?

Answer 29

Fishing quotas and controlled mesh size

Question 30

How do fishing quotas aid sustainable management ?

Answer 30

Limit the amount of certain fish species fisherman are allowed to catch and include international agreements.Conserve fish species by reducing number caught and killed so populations aren’t reduced to extinction

Question 31

What is a negative of fishing quotas ?

Answer 31

Fish of the wrong size or species are often thrown back into the sea dead or dying as they can’t legally be brought ashore

Question 32

How does controlling mesh size of nets aid sustainable management ?

Answer 32

Reduces number of discarded fish by letting them escape. Younger fish can slip through the net, survive and reach breeding age

Question 33

What is a negative of controlling the mesh size of nets ?

Answer 33

Determining net sizes can be difficult in areas where different fish species are fished for at the same time

Question 34

State 2 places where human activity is controlled

Answer 34

• Galapagos islands
• Antarctica

Question 35

How has human activity effected the Galapagos islands and how is it being controlled ?

Answer 35

Non native plants and animals introduced which compete with native species . Therefore, an eradication programme removed wild goats from smaller islands and visitors have to follow rules and visit with a licensed guide

Question 36

How has human activity effected Antarctica and how is it being controlled ?

Answer 36

Visitors caused pollution by dumping sewage which harms wildlife and hunting/whaling has reduced wildlife populations. Therefore, whaling is banned and waste must be taken away on ship as the area is protected