biology paper 2- ecology and environment Flashcards
define habitat
the place where an organism lives
define population
all the organisms of one species in a habitat
define community
all the different species in a habitat
define an ecosytem
all the organisms living in a particular area and all the non-living conditions
what are quadrats used for?
used to sample the distribution of organisms in their habitats
-used to estimate the population of an organism in different areas
how do you complete a quadrat?
- measure area of filed
- place a 1m^2 quadrat on the ground at a random point
- count all the organisms int he area
- place results in table
- multiply the number of organisms by the total area
how does the sample size affect the accuracy of the estimate?
the bigger the sample, the more accurate the estimate of the population
- better to use the quadrat at several points to get an average value for the number of organisms in 1m^2, then multiply by the total area
how can quadrats be used to investigate the distribution of organisms?
- laid out along a line called a transect
- make out the area you want to study
- collect data along the line using quadrats placed next to each other
producer?
makes its own food through photosynthesis
consumer?
eats producers- primary, secondary, tertiary
decomposer?
organisms that eat and breakdown dead and dying material and waste
what are pyramids of biomass?
shows the mass of living materials at that stage in the food chain
what are pyramids of numbers?
shows the number of organisms at that stage of the food chain
what are pyramids or energy transfer?
shows the amount of energy transferred to each trophic level in a food chain
how much energy is transferred to each trophic level?
10% because some parts of food are eaten and energy is taken in
some parts of food are indigestible so come out as waste
some is used for respiration
energy is lost as heat