B9 - ecosystems Flashcards
What is an ecosystem?
all organisms and the environment theyre in
example of an ecosystem
forest
what is a community?
A group of populations living and interacting in an area
example of a community
all the insects, birds, reptiles, rodents, deer, humans, plants…in an area
what is a population?
a group of individuals of the same species living in the same area at the same time
example of a population
pack of wolves
what is a habitat?
the natural environment of an organism
example of a habitat
tree for birds
what is meant by the term interdependent
populations that depend on eachother for resources
example of interdependence
Flowering plants depending on insects for pollination (reproduction) and insects depending on the flowering plant for food
What does abiotic mean?
non living factor
Examples of abiotic factors
temperature, wind, soil, sunlight, pollutants
What does biotic factors mean?
living factors
Example of biotic factors
predators, prey, competition
what does parasitism mean
an organism living on a host where the parasite benefits, (host is harmed)
what is meant by mutualism
an organism living on / with another, where both benefit from the relationship.
how are parasites dependant on the host?
The parasite takes what it needs from the host but the host doesnt benefit in return and is often harmed as a result.
example of parasitism
tick on a dog
example of mutualism
Tick bird and Rhinoceros - bird gets food (ticks) and rhino loses ticks
what is eutrophication
Excessive nutrients in a water body causing overgrowth of algae on surface causing all life under the surface to perish
how are non-indigenous species introduced ?
- introduced for food, or hunting
- by accident as stowaways on cargo.
disadvantages of introducing non-indigenous species
- bring new diseases,
- out compete indigenous species for food and resources.
How does fish farming effect biodiversity?
- food used to feed the fish and waste can leak into water sources, causing eutrophication
- breeding ground for parasites
- other organisms may become tangled in netting eg. seals
how does eutrophication affect biodiversity?
- surface run off causes nutrients to enter the water
- alge grows rapidly on the surface
- alge blocks sunlight from reaching organisms eg. plants.
- causes them to die so that organisms in the water dont have food and die as a result.
What does conservation mean?
The protection of forests, wildlife, and natural resources
what is meant by reforestation?
when a forest that was previously there is replanted to create a new forest.
examples of animal conservation?
protecting natural habitats, zoos, captive breeding programmes.
how does animal conservation maintain biodiversity?
- protecting natural habitats can mean that animals wont get harmed, or their homes wont be destroyed.
- caaptive breeding programmes in zoos are used to repopulate endangered species.
how does reforestation maintain biodiversity?
forests have high biodiversity, replanting them provides resources such as habitats and food for mant species.
what materials cycle through the eco system
water, carbon, nitrogen
What is evapouration?
the process of turning from water into water vapour due to increased temperature
What is condensation?
The change of state from a gas to a liquid eg. water vapour to water.
What is precipitation, give eg.
Any form of water that falls from clouds and reaches Earth’s surface. eg. rain, hail, sleet.
What is transpiration?
evaporation of water from a plant
the order of the water cycle
evaporation, condensation, precipitation
how is drinking water produced where there is lots of water?
pecipitation.
what is Desalination
the removal of salt from seawater to make it usable for drinking and farming
how is drinking water produced by desalination?
thermal desalination:
- salt water boiled,
- water evapourates, salt stays
- steam travels down a pipe
- condenses into pure water.
What is reverse osmosis?
a method of desalination:
Pressuring water though a partially permable membrane leaving the salt behind the filter
why is water important to living things?
moves substances through bodies, Cellular processes, growth.
What are decomposers?
Organisms that break down dead or waste material
Examples of decomposers
bacteria, fungi and worms
Describe the carbon cycle
1) Carbon dioxide enter the atmosphere through respiration and combustion
2) Carbon dioxide is absorbed by plants to make carbohydrates through photosynthesis
3) Consumers feed on plants passing the carbon compounds along the food chain
4) Most of the carbon consumed is released as carbon dioxide in respiration
5) When organisms die they are eaten by decomposers and the remaining carbon is returned to the atmosphere as carbon dioxide
-In some conditions decomposition is blocked; the plant and animal material may then be available as fossil fuel in the future for combustion
what are the key processes of the carbon cycle
photosynthesis, respiration, combustion
How do plants use nitrates?
to make proteins which is passed along the food chain as animals eat them.
What is the role of bacteria in the nitrogen cycle?
- decomposers: break down proteins in rotting animals to return nitrogen to the soil.
- nitrogen fixing: turn nitrogen into nitrates.
how do fertilisers increase nitrate content in soil?
- manure/ compost recycle nitrates left in plant/ animal waste by returning it to the soil.
- artificial fertilisers contain nitrates to return to soil.
why is bacteria important to soil fertility?
break down nutrients for soil.
How does crop rotation increase nitrogen content of soil?
instead of growing same crop all the time, different crops are grown in a cycle including nitrogen fixing crops such as peas to put nitraits back in the soil for other crops.
Advantages of Crop Rotation
keeps soil from going infertile, provides minerals
what are the stages of the food chain
producer, primary consumer, secondary consumer, tertiary consumer, top predator.
what is biodiversity
the variety of living organisms in an ecosystem
benefits of maintaining biodiversity
- protect food supply
- minimal damage to food chains
- future medicines (plants)
