B7 Ecology Flashcards
What is an ecosystem?
A community of plants and animals that depend on each other and interact with the abiotic (non-living) parts of the environment.
What do plants compete for?
Light, space, water, mineral ions.
What do animals complete for?
Food, mates, territory.
List 7 abiotic factors that can affect a community.
Light intensity, temperature, water, soil pH and mineral content, wind intensity and direction, carbon dioxide levels (plants), oxygen levels (aquatic animals).
List 4 biotic factors that can affect a community.
Availability of food, new predators, new pathogens, one species out competing another so there aren?t enough left to breed.
What is an extremophile?
An organism that lives in extreme conditions e.g. high temperatures, pressures or salt concentrations. E.g. bacteria round deep sea vents.
What are the levels of a food chain?
Producer –> primary consumer –> secondary consumer –> tertiary consumer
What is biodiversity?
A measure of the variety of all the different species in an ecosystem.
State 2 methods to determine the distribution and abundance of species in an ecosystem.
Random sampling using a quadrat. Sampling along a transect (a line) to see how the distribution changes.
Name 2 substances that are cycled in our atmosphere.
Carbon and water
Name 3 ways that carbon is returned to the atmosphere.
Respiration, combustion and decomposition (by microbes).
What takes carbon from the atmosphere?
Plants take in carbon dioxide.
What are the 3 main ways pollution can occur?
Water pollution ?e.g. sewage, fertilisers. Air pollution ?e.g. smoke, acidic gases. Land pollution ? e.g. landfill, toxic chemicals
What are the pros and cons of the use of peat as compost.
PROS: makes cheap compost for food production. CONS: destroys habitats, reduces biodiversity, releases CO2
What are the 2 main reasons for large-scale tropical deforestation?
Land needed for cattle and rice fields, to grow crops for biofuels.
