6.3.2 - Population and Sustainability

Question 1

Stages on population graph

Answer 1

Slow growth
Rapid growth - resources plentiful, reproductive rate > mortality rate
Stable state (no growth) - mortality = reproduction
Cannot support a larger pop. due to carrying capacity, small fluctuations

Question 2

Populations can

Answer 2

Remain stable
Rise or fall suddenly
Oscillate up and down w. the reg. pattern

Question 3

Types of limiting factors

Answer 3

Density independent

Density independent

Question 4

Density dependent

Answer 4

Factors that affect pop. the more they increase in size e.g resources, predators, intra and inter spp comp.
These limiting factors place the carrying capacity on population size

Question 5

Density dependent

Answer 5

Factors that affect the the same proportion of the population regardless of size

Question 6

Types of strategists

Answer 6

k and r

Question 7

K selection

Answer 7

Offspring have a high prob of survival 
Heavy parental care and nurturing
Larger organisms
Much lower reproductive rate
Young are altricial, longer lifespans and have overlapping generations

Question 8

Altricial

Answer 8

Born in an undeveloped state and requiring care and feeding by the parents

Question 9

R selection

Answer 9

Produce many low effort organisms
Species grow rapidly
Found in less competitive and low quality environments
Young are precocial
High of mortality so start reproducing earlier
Non overlapping generations, shorter lifespans
Boom and bust (cyclical)

Question 10

Precocial

Answer 10

Born in an advanced state and able to feed itself almost immediately

Question 11

Predator prey interactions

Answer 11

When predator pop increases, more prey eaten
Prey pop decreases, less food available for predator s
W/ less food, fewer predators survive so their pop. decreases
W/ fewer predators, fewer prey are eaten so their pop. increases
More prey = more food, predator pop. increases

Question 12

When does competition occur

Answer 12

When there are not enough resources to satisfy all of the organisms that depend on them

Question 13

How does intraspp comp affect population

Answer 13

Population drops –> comp. reduces –> pop. increases –> pop. drops (oscillates)

Question 14

Examples of interspp comp. affecting population

Answer 14

Red and grey squirrels - Invasive species

Question 15

Where does invasive species have a largest effect

Answer 15

Islands

Question 16

Competitive exclusion principle

Answer 16

2 competitive species cannot coexist at the same population level esp if ones staring population is higher than the other

Question 17

Preservation

Answer 17

Keeping habitats/species as they are now (assuming they are currently undisturbed)
Focuses on eliminating any human effects on ecosystems

Question 18

Conservation

Answer 18

Active management of ecosystems by humans to maintain biodiversity
Involves management of ecosystem so that natural resources can be used sustainably and reclamation

Question 19

Reclamation

Answer 19

Restoring ecosystems that have been damaged/destroyed

Question 20

Threats to biodiversity

Answer 20

Over-exploitation of ecosystems by humans
Habitat disruption and fragmentation
Intro of invasive species by humans that outcompete native species to extinction

Question 21

Potential management strategies

Answer 21

Raise carrying capacity by increasing nutrients 
Move individuals to enlarge pop
Encourage natural dispersion using dispersion corridors  between fragmented habitats 
Fencing 
Controlling predators and poachers
Vaccinate individuals 
Prevent pollution/disruption 
Intervene to restrict succession

Question 22

Ethical reasons to conserve

Answer 22

Moral responsibility
All organisms have a right to live
Every species has value in and of itself

Question 23

Why does interspp competition have diff effects in the wild

Answer 23

Species may migrate
Other biotic and abiotic effects on the organism
Availability of resources vary
Organisms may not have exactly overlapping niches