6.3.2 - populations and sustainability

Question 1

phase one of a population growth curve

Answer 1

a period of slow growth - the number of individuals that are present reproduce increasing the total population - the birth rate is higher than the death rate

Question 2

phase 2 of a population growth curve

Answer 2

a period of rapid growth - total population multiplies exponentially. no constraints act to limit the population explosion

Question 3

phase 3 of a population growth curve

Answer 3

a stable state - further population growth is prevented by external constraints - birth and death rates are approximately equal

Question 4

limiting factor

Answer 4

prevent the further growth of a population and in some cases cause it to decline.

Question 5

carrying capacity

Answer 5

the maximum population size that an environment can support

Question 6

immigration

Answer 6

movement of individuals into a particular area increasing population size

Question 7

emigration

Answer 7

movement of individual organisms away from a particular area decreasing population size

Question 8

density independent factors

Answer 8

factors that have an effect on the whole population regardless of its size, dramatically changing the population size (e.g. earthquakes)

Question 9

interspecific competition

Answer 9

competition between different species

Question 10

intraspecific competition

Answer 10

competition between members of the same species

Question 11

what is interspecific competition the result of?

Answer 11

reduction of the resource available for the populations.

Question 12

stages of intraspecific competition

Answer 12

1 - resource is plentiful, everyone can have enough to survive and reproduce so pop increases
2 - due to increased population, resources are limited meaning the population will decrease
3 - less competition means less organisms are competing for the same resources - more organisms survive and reproduce, resulting in population growth.

Question 13

predation

Answer 13

where a predator kills and eats prey.

Question 14

predator prey relationship steps

Answer 14

stage one - increase in prey population provides more food for the predators - increasing predators

stage two - more predators means a decline in prey population

stage three - less prey means less food for predators so predator population decreases

stage four - reduced predators means more prey

Question 15

why is the predator prey population not simple?

Answer 15

other factors will influence population size, like availability food, or the presence of other predators

Question 16

conservation

Answer 16

the maintenance of biodiversity through human action or management

Question 17

reclamation

Answer 17

the process of restoring ecosystems that have been damaged or destroyed

Question 18

preservation

Answer 18

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

Question 19

when is preservation needed?

Answer 19

in order to keep ecologically, archeaologically or palaeontologically sensitive resources

Question 20

economic importance of conservation

Answer 20

to provide resources that humans need to survive and provide an income - mecidinal drugs, clothes and food that can be traded

Question 21

social importance of conservation

Answer 21

many people enjoy the natural beauty of wild ecosystems as well as using them for activities which are beneficial to health by providing a means of relaxation

Question 22

ethical importance of conservation

Answer 22

all organisms have the right to exist and most play an important role within their ecosystem. many people believe that we should not have the rught to decide which organisms should survive. we also have a moral responsibility

Question 23

sustainable resource

Answer 23

renewable recourse that is being economically exploited in such way that will not run out

Question 24

aims of sustainability

Answer 24

• preserve the environment
• ensure resources are available for future gens
• allow humans in all societies to live comfortably
• enable less developed countries to develop