ECOLOGY Flashcards
What is the role of microorganisms in recycling materials?
Microorganisms help return minerals and nutrients back to the environment so that the materials can then be used by other organisms. As the bacteria and fungi decompose dead matter, they also respire and so release carbon dioxide to the environment, contributing to the carbon cycle.
What is decomposition/decay?
Decomposition, or decay, is the breakdown of dead matter.
How can differences in temperature affect the rate of decomposition?fridge?
At colder temperatures decomposing organisms will be less active, therefore the rate of decomposition remains low. This is why we keep food in a fridge. As the temperature increases, decomposers become more active and the rate of decay increases.
How can differences in water affect the rate of decomposition?
With little or no water there is less decomposition because decomposers cannot survive.
How can differences in oxygen affect the rate of decomposition?
Similar to water, decomposers need oxygen to survive and without it there is little or no decomposition.
How can decay lead to the production of biogas?
Anaerobic decay occurs when bacteria and fungi break down dead matter without oxygen. The products of anaerobic decay are methane and carbon dioxide. Together the methane and carbon dioxide produced are called biogas.
What is biodiversity?
The degree of variation of species in a certain area.
What is the impact humans have on biodiversity?how do we reduce it?
Overuse of fertilisers can cause eutrophication and reduces biodiversity.
Fish farming can reduce biodiversity.
Introduction of non-indigenous species can reduce biodiversity.
Deforestation and destroying of habitats can reduce biodiversity.
What is the need for biodiversity?
Without a wide range of animals, plants and microorganisms, we cannot have the healthy ecosystems that we rely on to provide us with the air we breathe and the food we eat. And people also value nature of itself.
What is the greenhouse effect?
The trapping of solar energy in a planet’s atmosphere by certain gases.
What are examples of greenhouse gases?
Methane.
Water vapour.
Carbon dioxide.
What is air pollution?
Combustion of fossil fuels and other fuels releases carbon dioxide. This contributes to the greenhouse effect and leads to global warming.
What is land pollution?
The rubbish we throw out that is not recycled goes into a land fill and can end up in the ocean.
What is water pollution?
Fertilisers are very soluble in water and are easily washed off fields by the rain and then into rivers etc. (eutrophication).
What are pollution indicators?
Indicator species are organisms that can tell us about the levels of pollution in an area by their presence or absence.
What is an example of a pollution indicator?
- no lichens = air is heavily polluted
- because lichen will grow more successfully where there is less air pollution.
Explain the rise in pollution?
Increasing human population has led to an increase in pollution:
more fossil fuels being burnt for heat and power
more food being grown
land taken over for industry and housing
What is the effect of pollution on plants and animals?
Air pollution can affect the growth of a plant and damage to respiratory systems of both animals and plants.
Eutrophication.
No clean water for animals or plants.
What is the impact of the destruction of peat bogs?
Peat bogs are a very important store of carbon. We call them carbon sinks . If all the peat was removed and burned this would quickly release a huge volume of carbon dioxide into the atmosphere and contribute to the greenhouse effect and global warming/climate change.
What are the impacts of deforestation?
Less biodiversity.
Carbon is released into the atmosphere as it is stored in trees and used for photosynthesis. If trees are cut down, carbon is released and contributes to global warming/climate change.
Flooding.
Loss of habitas.
What are the reasons for deforestation?
Extraction of materials (wood).
Agriculture and farming.
Cattle-grazing.
Plantations (palm oil)
What are the biological consequences of global warming?
Causes sea level to rise which will flood habitats animals and plants.
Melting of ice which will destroy habitats for polar bears and penguins.
Climate change so storms or drought.
What are detritivores?
organisms start the decay process by eating dead animals and plants, producing waste products (which fungi and bacteria feed off and adds nutrients to the soil).
What are decomposers?
Group of bacteria/fungi that feed on dead animals and plants.
Explain the recycling of materials.
Dead animal —> nutrients into soil from decomposers/detritivores —> plants absorb these through their roots —> plants are eaten by animals REPEAT
Explain the water cycle.
Evaporation
Condensation (moist air rises and cools into water droplets)
Precipitation (water droplets become heavier)
Respiration (loss of water vapour from plants and animals)
Transpiration (loss of water vapour from plants)
What are factors that increase the CO2 in the atmosphere?
Increase use of fossil fuels by humans.
Deforestation of peat bogs (they store carbon).
Deforestation of trees (less trees to absorb carbon and also releases carbon when burnt).
What does anthropogenic mean?
Things that are caused by humans.
How is land used by humans?
Obtaining materials from the ground.
Crops/agriculture.
Housing/hospitals/schools.
What can you use to measure water pollution.
Rain gauge.
Thermometer.
Oxygen meter.
Bio-indicators.
What is bioaccumulation?
This is when toxins build up in the food chain.
Name two mineral ions that are found in fertilisers.
Phosphate and nitrate.
What is the process of eutrophication?
increased nitrates from fertilisers in the water increase the growth of algae and plants
The decomposition process uses up the oxygen so the water becomes anoxic which causes fish and other animals to die.
Why don’t plants decay in peat bogs?
Because there is no oxygen (anaerobic conditions).
pH is too low for decay.
What does a catalytic convertor do?
Reduces the level of polluting gases that cars emit.
Describe the carbon cycle.
Animals and plants die.
Bacteria and fungi decay this which releases CO2.
Animals and plants respire which releases CO2.
Combustion releases CO2
CO2 then released in the air from the plants/animals and combustion and decay.
CO2 is taken in by photosynthesis.
What is a habitat?
The place where an organism lives
What is a population?
All the organisms of one species living in a habitat
What is a community?
The population of different species living in a habitat
What is an ecosystem?
The interaction of a community of living organisms with the non-living parts of their environment
What are examples of abiotic factors?
Moisture level
Light intensity
Temperature
Carbon dioxide level
Wind intensity and direction
Oxygen level
Soil pH
What are examples of biotic factors?
New predators
Competition
New pathogens
Availability of food
What is a structural adaption?
Adapting the features of an organisms body structure (shape/colour)
What is a behavioural adaption?
Adapting the way that an organisms behaves (e.g. migrate to warmer environments in winter)
What is a functional adaption?
Adapting the things that go on inside an organisms body (processes/reproduction/metabolism)
How do you find the mean number of a population using quadrats?
total number of organisms / number of quadrats
What can affect the distribution of an organism?
Change in availability of water
Change in temperature
Change in composition of atmospheric gases
What factors affect the rate of decay?
Temperature
Oxygen availability
Water availability
Number of decay organisms
What increase the rate of decay?
Warm temperature (increasing rate of enzymes) not too hot
Moist environment
Oxygen present
What is biogas mainly made up of?
Methane
How is biogas produced?
Microorganisms decay plant and animal waste anaerobically in a digester/generator
What are the two type of biogas generators?
Batch
Continuous
Why can’t we always protect biodiversity?
Conflict between protecting it and our food security
Costs money
Can affect people’s livelihood
Development is important
What are ways to protect biodiversity?
Breeding programmes
Programmes to protect and regenerate habitats
Programmes to reintroduce hedge grows
Reduce level of deforestation
People encouraged to recycle and reduce waste
What does each pyramid if biomass show?
The relative mass of living material at a trophic level
How does the earth remain at a warm temperature?
Gases in atmosphere act as insulating layer
Absorb and re-radiate energy in all directions (back to earth)
How do you calculate the efficiency of biomass transfer?
biomass transferred / biomass previously available
How is biomass transferred through a food chain?
When an organism eats another organism
What are some reasons that biomass can be lost between tropic levels?
Organisms don’t always eat every part of the organism they are consuming
Don’t absorb everything some is released as faeces
Some biomass is made into other waste substances that are lost e.g. urea or glucose
What is food security?
Having enough food to feed a population
What can impact the world food security?
Growing population
Increased imports from less developed countries so food becomes more scarce
Farming affected by new pests and pathogens or change in environmental conditions
High cost of farming
Conflicts
Why are fish stocks in the ocean declining?
Because we are overfishing so less fish to eat and affects food chains in ocean
How can overfishing be managed?
Fishing quotas
Net size
How do fishing quotas manage overfishing?
Limits on the number and size of fish that can be caught in certain areas
How does net size manage overfishing?
Different limits of the mesh size of fish net depending on what is being fished
Reduces number of discarded fish
How can food production be made more efficient?
Livestock and fish factory farmed
Animals fed high protein food to increase growth
How does limiting the movement of livestock make food production more efficient?
Livestock use less energy moving around and controlling body temp so more energy available for growth so more food from same input
What is mycoprotein used for?
To make high protein meat substitutes
What is mycoprotein made of?
Fungus which is grown in aerobic conditions on glucose syrup
This harvested and purified
What is biotechnology?
When living things/biological processes are used and manipulated to produce a useful product
What is genetic engineering?
Transferring a useful gene from one organism to another
How is bacteria genetically engineered to make human insulin?
by inserting the human gene for insulin production into their plasmids
What does a restriction enzyme do?
Recognises specific sequences of DNA and cut the DNA at these points
The cut leaves one of the DNA strands with unpaired bases (recognises patterns in DNA and cuts it off so scientists can study and modify genes)
What does a restriction enzyme do in the genetic engineering of a bacteria cell to make human insulin?
Cuts the insuline gene from human chromosome
Cuts plasmid from bacterium
What are the advantages of genetically modified crops?
Resistant to pests
Grow better in drought conditions
Provide more nutritional value
What are the disadvantages of genetically modified crops?
Countries may become dependant on companies who sell GM food
Poor soil means no crops will survive
