Ecology and the environment Flashcards
what is the habitat
the place where an organism lives
what is the population
all the organisms of one species in a habitat
what is a community
all the different species in a habitat
what is an ecosystem
all the organisms living/interacting together in a particular area, and the abiotic conditions
what is biodiversity
the variety of different species of organisms on earth, or in an ecosystem
list 2 abiotic factors
environmental conditions e.g. temperature
toxic chemicals e.g. pesticides or fertilisers
list 3 biotic factors
availability of food
number of predators
competition for resources
how can you use a quadrat to measure population size
place 1m quadrat on the floor at a random point
count all organisms within that quadrat
repeat steps 1 and 2 a lot
calculate a mean average
repeat in other areas
compare results
how can you use belt transects to study distribution across a habitat
e.g. plants in shade vs plants in sun
mark out a line in the selected area
collect data using quadrats placed next to each other/or in intervals
count all organisms selected within the quadrat or estimate percentage cover
record height of organism or any abiotic factors
repeat these steps and record a mean average of the organisms within the area
compare results and decide extend of abiotic factors effecting
what is a decomposer
an organism that breaks down dead material and waste
what does each bar of a pyramid of biomass represent
mass of living material at that stage of the food chain
describe how energy is transferred down the food chain
sun - plant - rabbit - fox
sun transfers energy to plants
plants use energy for photosynthesis to produce energy
this energy is passed down as rabbit eats plant and eachother
how much energy available to the next organism is lost
90%
how is energy lost as you moved down the tertiary levels
some parts of food e.g. roots or bones aren’t eaten so energy not taken in
some parts of food are indigestible so just pass through the body and removed as waste products
energy used for respiration and also transfers to surroundings as heat
outline the stages of the carbon cycle
carbon absorbed by plants for photosynthesis for carbon, lipids and proteins
when animals eat plants, carbon compounds are passed down
respiration releases carbon back to the atmosphere
microbes break down dead material release enzymes, decomposers release carbon back into the atmosphere as they respire
fossil fuels burned release carbon back into atmosphere
what is the benefit of decomposition
materials removed so habitats can be maintained for organisms to live in as waste products don’t just pile up
what is the effect of carbon monoxide
lack of air supply during fossil fuels burning produces carbon monoxide
it combines with haemoglobin in the red blood cells to reduce the amount of oxygen that can be carried
its mostly released in car emissions
what do catalytic converters do
convert carbon monoxide into carbon dioxide
how is acid rain produced
Sulfur dioxide produced by burning of fossil fuels (carbon dioxide and nitrogen oxides)
this reacts with rain clouds to produce dilute sulfuric acid
this falls as acid rain
it is mainly caused by combustion in cars and power stations
how does acid rain kill fish and trees
creates increased PH and acidic conditions in the lake.
damages leaves by acid make trees unable to take up nutrients
what is the greenhouse effect
gases in the atmosphere absorb suns heat and remit it in all directions
how is carbon dioxide produced
e.g. burning fossil fuels and cutting down trees
how is methane produced
cattle rearing, or rotting plants in marshland
how is nitrous oxide produced
vehicle engines, fertiliser, bacteria in soil
how are CFS produced
leaks in fridges
explain the forming of eutrophication
fertilisers enter the water to add extra nitrates and phosphates
this increases algae growth which blocks out the light
this means plants can’t photosynthesise due to lack of light, so they die
with more food available, microbes increase in number and deplete oxygen used up in water
so organisms that need oxygen die
describe soil erosion
trees hold soil together, when trees are removed, soil is washed away and ground is left infertile
describe leaching
leaching is when nutrients are washed away by rain, trees absorb the nutrients before this happens
describe evapotranspiration
water evaporating from earths surface and plants, this falls down as rain
