module 4

Question 1

Ecology

Answer 1

the interactions of one organism with another as well as their environment

Question 2

levels

Answer 2

Individual
Population
Community
Ecosystem
Biome
Biosphere

Question 3

abiotic factors

Answer 3

nonliving features of an environment
Light
Wind
Temperature
Water
Availability
pH levels → soil and water
Salinity
Humidity
Minerals

Question 4

biotic factors

Answer 4

living features of an environment

Predation
Competition (for resources)
Pathogens
Plants
Animals
Microbes

Question 5

nitrogen cycle

Answer 5

→nitrogen fixing bacteria that is present in soil that fixes atmospheric nitrogen → soluble nitrogen compounds → when in the soil → decomposers (eg. bacteria and fungi) converts it to useful compounds taken up by plants → plants use nitrogen to make protein and nucleic acids

Question 6

Carbon oxygen cycle

Answer 6

transfer of oxygen and carbon between living and non-living components of an ecosystem
Driven by photosynthesis (CO2 + H2O → (in presence of sunlight) C6H12O6) and cellular respiration (C6H12O6 + O2 → ATP + CO2 + H2O)

Question 7

Competitive exclusion principle

Answer 7

Two species can’t coexist if they are competing for the same resource → one species will outcompete the other species and the second species is eliminated

Question 7

Resource partitioning

Answer 7

species adapt to slight different niches so that they can coexist (different ecological niches but the same environment)
eg.red and yellow birds

Question 8

food chains

Answer 8

• represent simple feeding relationships between organisms in an ecosystem
• Shows predation arrow goes from the organism which is being eaten to the organism that eats it
• represents the flow of energy
  producer –> primary consumer –> secondary consumer –> tertiary consumer

Question 8

food webs

Answer 8

• culmination of food chains from the same ecosystem
• organisms can exist on more than one trophic level
• allows us to see the relationship between different organisms in an ecosystem
• can show detritivores and decomposers

Question 9

keystone species

Answer 9

• If it is reduced in numbers → potentially cause the ecosystem to collapse
• eg. cassowary –> spreads seeds across an ecosystem

Question 10

trophic levels

Answer 10

broad divisions of the different levels throughout an ecosystem
- arranged into ecological pyramids
- pyramids of biomass
- pyramid of energy
- pyramid of numbers

Question 11

pyramid of biomass

Answer 11

• loses about 10% of biomass as each trophic level goes higher
• compare matter

Question 12

biomass

Answer 12

total dry weight of organisms in trophic level

Question 13

pyramid of numbers

Answer 13

producer, herbivore, carnivore

Question 14

pyramid of energy

Answer 14

represent energy of the entire trophic level
- energy is lost due to metabolic reactions
- lost due to kinetic energy and heat

Question 15

how does extinction occur and mass extinction

Answer 15

ecological consequence –> loos f biodiversity –> loss of keystone species –> loss of ecosystems

• rate of extinction increases dramatically –> mass extinction due to human impacts (climate change, pathogens, introduced species and diseases, pollution)

Question 16

extinct animals

Answer 16

thylacine
- apex predator
- increase in prey numbers led to the reduction of producers
- competed with wild dogs
- loss of habitat
- new disease

Question 17

carrying capacity

Answer 17

the maximum number, density, or biomass of a population that a specific area can support sustainably

Question 18

allelopathy

Answer 18

• Process where allelochemicals are released by some sort of plant species to influence the germination of seeds, mortality of seedlings and the growth of neighbouring species
• Can be beneficial or harmful
• Prevents overcrowding → leaf litter increasing seedling mortality of eucalyptus

Question 19

competition

Answer 19

Two organisms compete for limited resources

Question 20

interspecific competition

Answer 20

two or more different species dependent on the same prey
- lion and cheetah

Question 21

intraspecific competition

Answer 21

competition for resources within the same species
- both fighting for sunlight

Question 22

predator

Answer 22

consumer organisms from another species

Question 23

prey

Answer 23

organism that was consumed

Question 24

disease

Answer 24

- Caused by the introduction of new species, stressors (pollution) - Population with genetic diversity will help populations against the disease Large genetic diversity → genetic variation → some with resistance to the pathogens → reproduce → population that is resistant - eg. Tasmanian devil facial tumour disease, amphibian chytrid fungus

Question 25

symbiotic relationships

Answer 25

- mutualism - commensalism - parasitism

Question 26

mutualism

Answer 26

relationship between different species which benefits both organisms - flowering plants and insects

Question 27

commensalism

Answer 27

relationship between two organisms in which one benefits and the other is unaffected - shark and remora fish

Question 28

parasitism

Answer 28

relationship in which one organism benefits and the other is harmed - parasite tape worm - host human

Question 29

distribution

Answer 29

where the species inhabits

Question 30

types of distribution

Answer 30

- random: resources are abundant - uniform: resources are scarce - clumped: protects for predation therefore gathers

Question 31

sampling

Answer 31

- transect mapping (distribution and sessile) - quadrat sampling (distribution and sessile) - capture-mark-recapture (abundance and sessile)

Question 32

abundance

Answer 32

number of organisms in a population at a certain time and place

Question 33

average number per quadrat

Answer 33

total organisms in all quadrats/ total number of quadrats

Question 33

total population

Answer 33

average number per quadrat X total area /area of quadrat or density (per m2) X total area

Question 34

capture remark recapture

Answer 34

mobile population abundance = number captured X number recaptured/number marked in recapture

Question 35

rock formations

Answer 35

explains continental drift

Question 36

aboriginal rock paintings

Answer 36

evidence of fauna and flora changing - shows how species have evolved and adapted

Question 37

ice core drilling

Answer 37

- cores taken from glaciers and polar caps are used to determine climate - shows the atmosphere at the time through trapped debris - frozen hydrogen and oxygen in the form of isotopes

Question 38

banded iron formations

Answer 38

- sedimentary deposits formed at the bottom - evidence of oxygenation (shows that the oxygen had no oxygen before)

Question 39

australia's species

Answer 39

reproductively isolated

Question 40

Sclerophyll plants

Answer 40

- adapted to abiotic factors of dry climate and nutrient deficient soil - thick waxy cuticle - eucalyptus

Question 41

Megafauna

Answer 41

an arbitrary compilation of relatively large mammalian, reptilian, and avian taxa, ranging in size from ~10 kg or less up to >2,000 kg eg. Thylacine Woolly rhinoceros Procoptodon - Evolved due to glacial conditions → extinct due to warmer temperatures from climate change → human induced (increased fire, reduction of grasslands, loss of freshwater)