Topic 7: Ecology Flashcards
Define individual
a single organism of a species
Define population
The total number of organisms of one species
Define community
All the living organisms in an environment
Define ecosystem
The interaction between the living and the non-living parts of an environment
Define stable community
It is a community where all the species, and environmental factors are balanced, so that population sizes remain fairly constant
Define interdependence
Within a community the species depend on each other for shelter, food, pollination, seed dispersal etc.
Name some biotics factors
New competitors
New pathogens
New predators
Availability of food
Name some abiotic factors
Temperature
Soil pH
Light intensity
Wind intensity
Mineral content
Moisture levels
Carbon dioxide levels
Oxygen levels
Define intraspecific competition
Members of the same species in a population are competing for the same resources
Define interspecific competition
Between individuals of different species within the same habitat or niche competing for the same resources
What are structural adaptations?
Physical features of an organism, e.g. sharks have sharp teeth for killing prey
What are behavioural adaptations?
Are how the organism behaves, an e.g. animals in hunting packs - wolves
What are functional adaptations?
Are how the body operates e.g. is sweat being produced or toxins
How are animals adapted to live in hot climates?
Thin fur
Little urine produced
Long limbs
Little body fat to lose heat by radiation
How are animals adapted to live in cold climates?
Thick fur
Blubber
Big feet
Body fat to conserve heat loss
How are plants adapted to live in hot climates?
Less leaves/ small leaves to reduce water loss
Long roots to absorb more water
What type of environments do extremophiles live in?
Environments with:
High temperature
High pressure
High salt concentration
Describe the order of food chains starting from the producer
Producer
Primary consumer
Secondary consumer
Tertiary consumer (predator)
Describe what happens when an apex predator dies
- When an apex predator dies, their body decomposes into the ground and the nutrients goes to the environment
- In decomposition, maggots, woodlice, earthworms etc. help chop up the dead organism and microorganisms break it down even more, so the nutrients and minerals go down to the environment
e.g. minerals into the soil or carbon in the air - Cycle repeats
Describe the method of estimating populations
- find the area of your quadrat
- find the area of your site
- divide the area of the site by the area of the quadrat - this is your multiplication factor
- place the quadrat randomly using a random number generator and coordinates
- count and record the number of organisms
- take at least 10 samples
- work out the mean number of organisms in each quadrat
- multiply up to estimate the total number in the site
How can we improve accuracy when estimating populations?
Bigger quadrats
More quadrats
Random sample sites
Describe the percentage cover method
- a simple way of measuring an organism is to calculate percentage cover
- this is especially useful if it is hard to count all the individual organisms within a quadrat
- quadrats are placed and the number of little squares that are covered by plants are counted
- only count the squares more than half covered and estimate the others
- divide total number of squares and x100 to give a percentage
Describe the method of sampling along a transect line
- a transect line is used when you are trying to investigate the effect of a changing factor (biotics or abiotic) over a distance
- quadrat readings are taken along a ‘line’ starting at one point and at various distances from it
- this line is a transect line
- multiple, random readings should be taken at each point to ensure representative data free from bias
Describe the water cycle
- evaporation happens from the surface of the water
- transpiration happens in plants
- the water vapor rises into the atmosphere where clouds form
- the water vapour condenses
- water falls as precipitation
- the water then runs off the surfaces and collects as ground water or in bodies of water
What are the conditions needed for decay?
Moisture
Warm conditions/ warm temperatures
Oxygen
Bacteria
Microorganisms present - they produce enzymes which digest the material and they can then absorb it. They are called saprophytes
Define decay
Decay is when complex materials break down into more simple molecules which can then be reused
Describe the process of decay
- detritivores such as worms and woodlice start the process of decay by feeding on the dead matter
- decomposers such as bacteria and fungi will also feed on the dead matter
- both the detritivores and decomposers will use some of the nutrients from the dead matter for growth but will also respire and release waste products into the surroundings
- waste products can be used by plants for growth
What are the features of a compost bin?
Open at the bottom
Loose fitting lid
Air hides
Dark coloured
Biogas Generator
Anaerobic decay produces methane gas
There are different types of anaerobic respiration
Methane can be used as a fuel
What is a hypothesis?
a prediction that you can then test
Describe the method for the decay required practical
1- add phenolphthalein to a boiling tube with 5cm^3 milk
2- add 7cm^3 sodium carbonate to the milk tube
3- put the tubes in a beaker of water of 10 degrees and leave for 5 minutes
4- add lipase to the milk mixture and start the stopwatch. Time until the colour changes from purple to yellow
5- repeat steps 1-5 using temperatures of 20-60 degrees going up in 10 degrees each time
Control - Keep the volume of lipase the same, the volume of milk the same and the number of drops of indicator the same
Decay Required practical:
Why do we add phenolphthalein to a boling tube with 5cm^3 milk?
So that the indicator turns from pink/purple to yellow when solution turns from alkali to acidic
Decay Required practical:
Why do we add 7cm^3 sodium carbonate solution to the milk tube?
To make sure the solution is alkaline to begin with to see a clear colour change
Decay Required practical:
Why do we put the tubes in a beaker of water of 10 degrees and leave for 5 minutes?
To allow the liquids to come to temperature
Decay Required practical:
Why do we add lipase to the milk mixture and start the stopwatch and time until the colour changes from purple to yellow?
so we can time the rate of decay
Decay Required practical:
Why do we repeat steps 1-5 using temperatures of 20-60 degrees going up in 10 degrees each time?
Our independent variables is temperature as we are trying to see the effects of temperature in decay (minimum of 5 needed)
Decay Required practical:
Why do we keep the volume of lipase the same, the volume of milk the same and the number of drops of indicator the same?
The volume is a control variable to keep the practical a fair test
What do pyramids of biomass show?
These show the total dry mass of the organisms at each trophic level. They are always a pyramid shape
Why is energy reduced at each trophic level?
- respiration - uses glucose absorbed and some biomass is lost as CO2
- excretion - biomass is lost as water and urea are excreted
- not all material is eaten
- some of the eaten material cannot be digested and is lost in faeces
What are the advantages of the factory farming technique?
- increased profit/ efficiency/ greater food production/ cheaper food/ faster growth
- farmers can have more livestock
- less energy is lost through movement
- less energy is used keeping warm
- food is high in calories/ protein, so animals will grow faster/ lay more eggs
What are the disadvantages of the factory farming technique?
- aggressive behaviour
- emotional stress reduces productivity
- faster spread of disease
- antibiotics in the food chain/ residual Chemicals in the food chain
- costs of heating
What is food security?
Having enough food to feed a population
Name some biological factors that may threaten food security
Increasing birth rate
Changing diets in developed countries - scarce food is transported
New pets and pathogens affecting farming
Environmental changes
What is biodiversity?
The variety of all different species of organisms on earth or within an ecosystem
What is the impact of waste?
- sewage - chemicals/ parasites enter water. Bacteria take all O2
- eutrophication - caused by fertilisers, algae block the light then die
- smoke and gases - soot, acid rain
- toxic chemicals - bioaccumulation
Describe how the impact of waste can lead to pollution
- in water - sewage and chemicals
- in the air - smoke and sulphur dioxide
- on land - toxic chemicals and household waste
Describe what happens during eutrophication
- Fertilisers or sewage pollute water, algae grows rapidly
- Bacteria decompose algae and use up oxygen during respiration
- Animals die from the lack of oxygen
- Algae die as too much algae for sunlight to reach all and photosynthesis is affected. Dead algae rot and and fall to the bottom
Destruction of peat bogs:
1) What is it?
2) Why do we do it?
3) Impact
1)
- very wet areas of land without trees in which many types of mass grow
- they’re acidic and very low in nutrients
- form in marshy areas when decomposers cannot completely break down plants
2)
- used as a fuel
- used as a cheap compost by gardeners - improve soil quality and increase food production
3)
- loss of habitat and decreased biodiversity, loss of carbon store
- destroyed faster than it’s made
How can we maintain biodiversity?
- replanting trees or plants
- recycling
- decrease of pollution
- having areas which are restricted or protected from building or deforestation
- breeding (selective breeding) - breeding programmes
- protection and regeneration
- field margins and hedgerows
- government targets
- recycling
What do breeding programs increase?
The populations of endangered species
e.g. the giant panda
What is regeneration?
For every tree that is cut down, another tree is replanted. Reduces CO2 levels and oxygen levels increase
What do field margins and hedgerows do?
Increases soil fertility, stops erosion and provides habitats, an e.g. planting hedgerows in the middle of large fields
What do government targets do?
Reduce levels of activities that damage the environment, an e.g. reducing CO2 emissions
What does limiting resources do?
Less waste is produced and sent to landfill
e.g. recycling and reusing
What does regeneration and protection do?
Provides more places for a species to live
Protecting the stocks:
What does net size (holes in the net were increased) allow?
This allows more smaller, immature baby fish to swim/ get away/ avoid being caught so they can grow and reproduce
Protecting fish stocks:
What does fishing quotas allow?
Only a certain number are allowed to be caught
There are still enough fishes left to breed
Describe how biotechnology works
- the fungus Fusarium is used to produce mycoprotein which is an alternative protein source to meat
- it is grown on glucose syrup in aerobic conditions
- the biomass is then harvested and purified
