Populations and Sustainability

Question 1

What are the two axis of the population growth curve?

Answer 1

x = time/number of generations
y = population size

Question 2

What is Phase 1 of the population growth curve?

Answer 2

(lag phase)
slow growth and low population

Question 3

What is Phase 2 of the Population growth curve?

Answer 3

(LOG/exponential phase)
rapid growth of the population, no constraints to act as a limit

Question 4

What is Phase 3 of the Population growth curve?

Answer 4

(Stationary phase)
a stable state is reached where the birth rate and death rate is equal and there is only fluctuation due to predator prey cycles
reaches carrying capacity

Question 5

What is meant by carrying capacity?

Answer 5

max number of the population that can exist in one place

Question 6

How is population growth % calculated?

Answer 6

population change during the period (DIVIDED BY) population at the start of the period

x100

Question 7

What are the limiting factors that prevent the further growth of populations?

Answer 7

• abiotic factors = non-living including temp, light, pH, AVAILABILITY of water and oxygen and humidity
  -biotic factors = living factors including predators, disease and competition

Question 8

What is meant by immigration? How does it impact on population sizes?

Answer 8

the movement of individual organisms into a particular area increases pop size

Question 9

What is meant by emigration? How does it impact on population size?

Answer 9

the movement of individual organisms away from a particular area decreases the population size

Question 10

What is meant by density independent factors?

Answer 10

factors that have an effect on the whole population regardless of its size, can dramatically change the size of populations

Question 11

What are some examples of density independent factors?

Answer 11

natural disasters i.e. floods, fires, tectonic hazards

Question 12

What is meant by density dependent factors?

Answer 12

Factors that fluctuate in severity depending on the size of the population

Question 13

What are some examples of density dependent factors?

Answer 13

• competition for food, water, mates
• disease

Question 14

What is meant by competition?

Answer 14

when 2 or more individuals are looking for the same resources e.g. water, food, shelter when they are in short supply

Question 15

What is meant by interspecific competition?

Answer 15

competition between DIFERENT species (for the same resource)

Question 16

What is meant by intraspecific competition?

Answer 16

competition between members of the SAME species

Question 17

What type of competition is competitive exclusion principle linked to, and what does it mean?

Answer 17

linked to INTERspecific competition

means… where two species are competing for limited resources, the one that uses the resources more effectively will dominate over the other

Question 18

Draw the graph that shows the effects of intraspecific competition on population size?

Answer 18

Picture on phone taken 16.04.2025

Question 19

What is the first stage of the graph for INTRA specific competition?

Answer 19

when resources are plentiful in habitat, all organisms have enough to survive and reproduce = increase in pop size

Question 20

What is the second stage for the graph of INTRA specific competition?

Answer 20

as a result of the increased pop, more individuals to share space and resources with

resources now limited.
population size will decrease

Question 21

What is the third stage of the graph for INTRA specific competition?

Answer 21

Smaller pop = less competition exists which means less organisms are competing for the same resources
organisms can survive and reproduce = increasing pop

Question 22

What is meant by predation?

Answer 22

this is where an organism (predator) eats another organism (prey)

Question 23

What type of competition is predation?

Answer 23

INTERspecific

Question 24

What are predator prey relationships?

Answer 24

predator no.s are always lower than prey, because predators eat more than one prey

Question 25

What is meant by conservation?

Answer 25

means the maintenance of biodiversity through human action or management includes maintaining diversity between species, within species and the maintenance of habitats

Question 26

What is meant by preservation?

Answer 26

is the protection of an area by restricting or banning human interference, so the ecosystem is kept in its original state

Question 27

What is a sustainable resource?

Answer 27

a renewable resource that is being economically exploited in such a way that it will not diminish or run out

Question 28

What are the aims of sustainability?

Answer 28

- preserve the environment - ensure resources are available for future generations - create an even balance in consumption of different countries

Question 29

What is meant by grazing ?

Answer 29

a method of feeding in which a herbivore feeds on plants such as grass and other multicellular organisms like algae

Question 30

What is meant by ecotourism?

Answer 30

tourism directed towards natural environments, to support conservation efforts and observe wildlife

Question 31

What is a species?

Answer 31

a group of organisms that share a genetic heritage, are able to interbreed and create fertile offspring

Question 32

What is meant by Ex-situ conservation?

Answer 32

'off site/out of place' is a technique that involves the transfer of target species away from its native habitat to a place of safety

Question 33

What is meant by In-situ conservation?

Answer 33

in the natural environment, confined in the sight of origin without the invasion of neighbouring tissues

Question 34

What are the social reasons for conserving a species?

Answer 34

- people enjoy being outside - recreational, aesthetic - people can do different activities in nature - protecting planets resources

Question 35

What are the economic reasons for conserving a species?

Answer 35

- many of the medicines used today are from plants - e.g. cancer fighting drugs - ecotourism is a major source of income for many countries

Question 36

What are the ethical reasons for conserving a species?

Answer 36

- all organisms have a right to exist, play important roles within ecosystems - have a moral responsibility for future generations to conserve the wide variety of naturally existing ecosystems

Question 37

What is meant by coppicing?

Answer 37

this is when trees are cut down to shrubs which stimulates growth, causing multiple branches to form, helping them to grow and expand

Question 38

What is meant by Pollarding?

Answer 38

when you remove the upper branches of a tree - promotes growth of a dense head of foliage and branches - keeps the height of the tree controlled - produces a cluster of branches that can grow from stumps at desired heights

Question 39

How does small scale sustainable timber production work?

Answer 39

- coppicing is often used - shoots that grow after cutting, more grow - rotational coppicing happens in many woodlands = woodland divided into sections, only cut some so that all are coppiced - rotational coppicing maintains biodiversity as the trees never grow enough to block out sunlight of others

Question 40

How does large scale timber production work?

Answer 40

based around the felling technique in large areas of forest - sustainable practice is maintained by selective cutting - replacing trees by replanting - plants can be grown at optimal condition to prevent competition - can manage disease and pesticides

Question 41

What are the disadvantages of using long term sustainable timber production?

Answer 41

- habitats are destroyed, soil minerals are reduced -soil is left susceptible to erosion - trees are important for maintaining nutrient balance

Question 42

What are three different potential strategies to sustainably fish?

Answer 42

- having different sized mesh nets - allow fishing at certain times of the year - limit the number of fish caught