Ecology Flashcards
Define Ecology
study of interactions between living things and their environment
Define Biosphere
part of the earth containing living organisms
Define Ecosystem
group of clearly distinguished organisms that interact with their environment
Define Habitat
place where an organism lives
Define abiotic factors and give 2 examples
non-living factors
eg: soil pH, edaphic factors
Define biotic factors and give 2 examples
living factors
eg: food, competition
What is pyramid of numbers?
represents the number of organisms at each stage in a food chain
What is meant by trophic level?
feeding stage in a food chain
Define edaphic factors
soil factors
What is meant by symbiosis
two organisms from different species that live in close association where at least one of them benefits
What is meant by nitrogen fixation
Conversion of nitrogen gas to nitrates
What is meant by nitrification?
conversion of nitrogen into nitrites and nitrates
What is the function of nitrogen cycle?
so it can be absorbed by organisms
Give 2 factors that influence the size of the human population
- Famine
2. War
If the population of prey declines suggest two possible consequences for the predators
- Less predators
2. Might migrate where there are more prey
What is the principal source of energy for the earths ecosystems?
sun
State one way in which a named organism is adapted to the ecosystem
fox- red fur for camouflage
What is meant by competition?
when organisms actively struggle for a scarce resource and only one of them wins
A relationship between two organisms in which both benefit is called
symbiosis
two sources of the carbon dioxide that are found in the atmosphere
- respiration
2. rocks
pollution
any harmful addition to the environment
Give an example of pollution and describe how this form of pollution can be controlled
animal waste
spread slurry on dry land
Give an example of human activity that results in the pollution of water
too much fertiliser is spread on grassland
fertiliser gets washed in the rivers/lakes
It causes algae to grow
when algae dies the oxygen gets used up and all living things die (eutrophication)
what is meant by conservation
wise management of our existing natural resources in order to maintain biodiversity