B7 Ecology Flashcards
Define the term ecosystem.
An ecosystem includes all of the living things interacting with each other, and also with their non-living environment.
Give an Example of an Abiotic factor
Abiotic factors are the non living components of an ecosystem so things such as the soil pH, light levels, wind speed, water content etc.
Define a ‘Community’
A group of organisms or a population of different species occupying a particular area.
Name a producer on this food web
The Grass.
Name a secondary consumer on this food web.
snake or lizard
What are the mising labels on the water cycle? Starting with the arrows up from the sea to the sun and working clockwise.
Evaporation, Condensation, precipitation.
What is a detritovore?
An organism that eats detritus (decaying matter).
What is a saprophyte?
A fungus or plant which feeds on detritus by secreting enzymes which help digest the detritus.
Name a process which locks carbon away.
Photosynthesis or sedimentation
Name a process which adds carbon to the carbon cycle
Respiration or Combustion
What does ‘biodiverse’ mean?
An area with a large number of different species living there.
What is a pesticide?
A chemical which kills pests, used in farming methods.
What is a herbicide?
A chemical used in agriculture which kills weeds.
What can cause algal blooms in lakes and result in Eutrophication?
Fertilisers
Name a gas responsible for causing acid rain.
Sulpher or nitrogen oxides.
What produces sulphur dioxide responsible for acid rain?
Cars and factories.
Name an effect of acid rain on the environment.
Limestone buildings and grave stones worn away, trees die, lakes too acidic for fish to survive.
Name a fossil fuel
natural gas, coal, oil.
What effect does the action of destroying peat bogs have on the gases in the atmosphere?
Increases the amount of carbon dioxide.
Describe one effect of deforestation on the environment.
Destroys habitats
reduces biodiversity
disruption of food chains
Name a gas responsible for Global warming.
Carbon dioxide, Methane.
What are Trophic Levels?
TRIPLE ONLY
They are the feeding levels within a food chain.
What is a top or ‘Apex’ predator?
TRIPLE ONLY
A predator that has no predators of its own.
Where is trophic level one found on a pyramid of biomass?
TRIPLE ONLY
At the bottom.
Why is most energy lost between the transfer from producer to consumer?
TRIPLE ONLY
Much of the plant material (cellulose) is indigestible and is simply excreted.
Calculate the missing respiration value.
TRIPLE ONLY
100-63-4 =33KJ
Calculate the efficiency for this diagram.
TRIPLE ONLY
Only 4 kJ of the original energy available to the bullock is available to the next stage, which might be humans. The efficiency of this energy transfer is:
efficiency = 4⁄100 × 100 = 4%
Give two possible negative effects of the decrease in forest cover on ecosystems.
any two from:
- decreased biodiversity
- loss of habitats
- increased carbon dioxide (concentration)
- global warming
What are ‘extremophiles’?
Some organisms live in environments that are very extreme, such as at high temperature, pressure, or salt concentration.
Bacteria living in deep sea vents are extremophiles.
What are the conditions needed for rapid decay?
TRIPLE ONLY
Heat, Moisture and Oxygen.
Why has large scale deforestation in tropical areas occured?
Large-scale deforestation in tropical areas has occurred to:
provide land for cattle and rice fields
grow crops for biofuels
Describe one way in which the efficency of cattle farming could be improved.
TRIPLE ONLY
The efficiency of food production can be improved by restricting energy transfer from food animals to the environment.
This can be done by limiting their movement and by controlling the temperature of their surroundings
Describe two methods which maintain fish stocks at sustainable levels.
TRIPLE ONLY
Control of net size and the introduction of fishing quotas play important roles in conservation of fish stocks at a sustainable level.
