3.5 - Population Size & Ecosystems Flashcards
(22 cards)
What is meant by “niche”?
A niche is an organism’s role in its ecosystem. This applies particularly to its feeding role.
What is meant by a “community”?
A community is all of the organisms of
all the different species living together in an ecosystem.
What is meant by a “biosphere”?
The total area on earth that can support life
What is meant by “niche differentiation”?
When an organism adjusts its requirements to avoid competition.
What is meant by “realised niche”?
The actual area a species is restricted to.
What is meant by “fundamental niche”?
The potential area of environment a species could exist if, if there are no other species.
Place the geographical terms for ecological areas in the correct order of size, starting at the smallest and ending with the largest.
microhabitats
habitats
zones
biomes
biogeographical region
biosphere
What is meant by “population”?
The number of individuals of the same species.
What happens as an organism becomes more specialised?
It becomes more effective but the niche becomes more restricted
`What is the difference between biotic and abiotic?
Biotic = living
Abiotic = non-living
What is an ecosystem?
A characteristic community of interdependent species interacting with the abiotic components of their habitat.
What are trophic levels?
Links of the food chain
What do food chains show?
show the transfer of energy as biomass
How is the energy passed through the food chain?
Photosynthetic organisms trap and convert solar energy into chemical energy which passes from organism to organism
What do producers do?
They convert the sunlight energy into carbohydrates, which are the food, and therefore the energy source for successive organisms in the food chain. They trap solar energy and synthesise sugars from inorganic compounds by photosynthesis
What happens at each trophic level of the food chain?
Energy is lost as waste
What are saprobionts?
Organisms which derive their energy from dead and decaying organisms i.e. detritivores and decomposers. They contribute to the recycling of nutrients
What are detritivores?
organisms such as earthworms and woodlice that feed on fragments or organic debris. This is detritus, the remains of dead organisms and fallen leaves
What are decomposers?
Microbes such as bacteria and fungi that obtain nutrients from dead organisms and animal waste. They complete the process of decomposition started by detritivores
What is the difference between decomposers and detritivores?
Detritivores are animals that eat dead organic matter (detritus). Decomposers, on the other hand, are primarily microorganisms (bacteria and fungi) that chemically break down dead organic matter
Decomposer = extracellular digestion
Detritivore = eats dead material
Why are food webs more useful than food chains?
They provide more information about the feeding relationships of organisms, as most animals feed on more than one type of organism but a chain cannot show this.
Which types of organisms are producers –> P consumers –> S consumers
producers are autotrophs
primary consumers are herbivores
secondary consumers are carnivores
consumers are heterotrophs
