Ecology Test Flashcards
What is a habitat?
A place where animals and plants naturally live and grow
What is an ecosystem?
A community of organisms in a given area and the abiotic factors that affect them
What is a niche?
A habitat that supplies the factors necessary for existence; the role of the organism
Abiotic factors
All the nonliving factors in an ecosystem
Biotic factors
All the living factors in an ecosystem
What is a population?
A group of organisms belonging to the same species that live in a particular area
Density dependent population factors
Factors triggered by overpopulation or overcrowding
Density independent population factors
Factors that occur regardless of the population
What do all organisms need to survive and how do they acquire it?
Energy by cellular respiration and photosynthesis
What are autotrophs?
They are “self feeders” aka producers
What are heterotrophs?
They are “other feeders” aka consumers
Herbivore feeds on
Plants
Omnivore feeds on
Plants and animals
Carnivore feeds on
Animals
Scavenger feeds on
Dead animals
Decomposer
Breaks down and absorbs dead organisms and wastes
What is a food chain?
Illustrates the flow of energy through an ecosystem
What amount of energy is transferred from each tropic level to the next?
10%
How much energy is lost through biological processes or as heat?
90%
The first trophic level
Producer- produces own food
The second trophic level
Primary consumer (herbivore) - eats plants/producers
The third trophic level
Secondary consumers (carnivores and omnivores) - eats the herbivores
The fourth trophic level
Tertiary consumer (carnivores and omnivores) - eats other carnivores
What is symbiosis?
A relationship between organisms of different species
Commensalism
A symbiotic relationship in which one species benefits and the other is unaffected
Mutualism
A symbiotic relationship in which both species benefits
Parasitism
A symbiotic relationship in which one species benefits and the other is harmed
Carbon cycle
Cycled by cellular respiration and photosynthesis
Nitrogen cycle
Transfer of nitrogen and nitrates from the atmosphere to soil to animals
How do humans affect the nitrogen cycle?
By using fertilizer and burning things (wood, fossil fuel) - increases greenhouse effect
