Unit 3 Topic 2 Flashcards
Define a Heterotroph
They obtain organic compounds from autotrophs or other heterotrophs.
Identify the different categories of Heterotrophs
Herbivores, Carnivores, Parasites, Detritivores, Decomposers.
Recall the percentage of energy transferred formula
(Net productivity of the organism / Net productivity of the previous trophic level) x 100
Recall the stages of the water cycle
Evaporation, Condensation, Precipitation, Transpiration, Photosynthesis.
Recall the stages of the carbon cycle
Combustion, Respiration, Photosynthesis.
How does nitrogen enter the soil via the nitrogen cycle?
Denitrification, Ammonification, Nitrification, Lightning, Fertilizers.
Define Denitrification
Decomposers break down faeces and dead organisms and return nitrogen to soil as ammonia.
Define Ammonification
Bacteria in soil/roots of legumes fix nitrogen into ammonia.
Define Nitrification
Bacteria in soil converts ammonia into nitrite/nitrate ions
Define a Niche
The role and space that an organism fills in an ecosystem, including all its interactions with the biotic and abiotic factors of its environment.
Define Interspecific Competition
Organisms of different species compete for the same resources.
Define Intraspecific Competition
Different individuals of the same species compete for resources.
Define Competitive Exclusion
One species successfully utilizes a resource at the exclusion of another, they cannot both use the resource.
Define a Keystone Species
A species that plays a critical role in maintaining the structure and functioning of their ecosystem.
Define Carrying Capacity
The size of the population that can be supported indefinitely on the available resources and services of that ecosystem.
Define Limiting Factors
Any factor that limits the size of a population, either biotic or abiotic.
Identify some biotic limiting factors
Food. Water. Shelter. Mates.
Identify some abiotic limiting factors
Space. Availability of nutrients and water. Pollution. Natural Disasters. Extreme Climatic Events.
Define Growth rate and change
Population density and distribution are influences by many abiotic and biotic factors.
What processes can affect the size of a population?
Natality. Morality. Immigration. Emigration.
Recell the population growth rate formula
= (Birth rate + Immigration rate_ - (Death rate + emigration rate)
What is Ecological succession?
The sequence of change in an ecosystem, where one kind of community is replaced by another more complex one.
What is a Sere
Successive communities in changing ecosystems.
Define Primary Succession
The initial colonization of a previously uncolonized area.
