Ecology Flashcards
What is a biotic factor?
Living factors of the environment eg -food -new Predators arriving -new pathogens -one species outcompeting another
What is an abiotic factor?
Non-living factors of the environment eg temperature Light intensity Moisture level Soil pH Oxygen levels
What is interdependence?
In a community, each species depends on the other species for things such as food, shelter, pollination and seed dispersal
What will happen if there is a change in abiotic factors?
A change in the environment could be an increase or decrease in an abiotic factor which can affect the sizes of populations in a community
What would happen if there was a decrease in light intensity, temperature or levels of CO2?
It could decrease the rate of photosynthesis of a plant species because enzymes it needs for photosynthesis could be denatured if too hot
What could happen if you decrease the mineral content of the soil?
Could cause nutrient deficiencies in a species of a plant which could affect the growth of a plant and cause a decrease in the population size
How are polar bears adapted to live in a cold, Arctic environment?
- thick layer of black blubber under their fur coat
- thick fur keeps them insulated and camouflaged with snow
- small ears to retain heat and decrease amount of heat loss
- their behaviour
What is a structural adaptation?
Features of an organisms body structure such as the shape or colour
What is a behavioural adaptation?
The way organisms behave. Many species will migrate to warmer climates during winter to avoid cold conditions
What is a functional adaptation?
Things that go on inside an organisms body that can be related to processes such as reproduction and metabolism
What is an organism that lives in extreme conditions?
An extremophile
Eg bacteria in deep sea vents
What is a producer in a food chain?
-at the start of the food chain
-produce their own food using energy from the sun
Eg green plants or algae- use photosynthesis
How is biomass created?
- when a greenplant produces glucose, some of it is used to make other biological molecules in the plant
- these molecules are the plants biomass-the mass of living material
How is energy transferred in an ecosystem?
It is transferred through living organisms in an ecosystem when organism eat other organisms
What is a food chain made up of?
Producers –> primary consumers –> secondary consumers –> tertiary consumers
What limits the population of any species?
It is usually limited by the amount of food available.
- if population of prey increases, then so will the population of predators.
- if population of predators increases, the number of prey will increase
What is the purpose of a quadrat?
It compares how common an organism is in two sample areas
How is a quadrat used?
- place it on the ground at a random point within first sample area
- count all organisms within the quadrat
- repeat these steps many times
- work out the mean number of organisms per quadrat in first sample area
What is the abundance?
The population size of an organism
What is the distribution?
Where an organism is found
- can use quadrats and compare
- can use transects
What is the purpose of a transect?
To find out how organisms(like plants) are distributed across an area
-can be used in any ecosystem
How is a transect used?
- mark out a line in the area you want to study using a tape measure
- collect data along the line by counting all the organisms you’re studying that touch the line
- or you can collect data by using a Quadrat
How do you work out the percentage cover of a quadrat?
- count the number of squares covered by the organism (Has to be more than half covered for a square)
- make this into a percentage and divide by the total number of squares in the quadrat
- multiply by 100 to get your percentage %
Which environmental changes affect the distribution of organisms?
- temperature
- availability of water-little rainfall means less water available
- composition of atmospheric gases- more air pollution affects this
How does the water cycle work?
- energy from sun makes water evaporate from sea turning it into water vapour
- warm water vapour is carried upwards and it eventually cools and condenses to form clouds
- water falls from clouds as precipitation (rain, snow, or hail) onto land where it provides fresh water for plants and animals
- then drains back into the sea and process starts again
What does the water cycle enable?
Means that the water on planet earth is constantly recycled and so there is an endless water supply
-continuous process
Why do materials decay?
They’re digested by microorganism which happens faster in warmer, aerobic conditions
What happens to materials in a stable community?
Materials that are taken out of the soil and used by plants are balanced by those that are put back in. There’s a constant cycle happening
How does the carbon cycle work?
- Atmospheric Co2 is removed from atmosphere by green plants and algae during photosynthesis
- carbon is used to make glucose that makes up the bodies of algae and plants
- when plants and algae respire, some carbon is returned to atmosphere as Co2
- when algae and plants are eaten by animals, some carbon becomes part of fats and proteins in their bodies and so carbon moves through food chain
- when animals respire, some carbon is returned to atmosphere as Co2
- when animals die, deritus feeders and microorganisms feed on them and so CO2 is returned to atmosphere when they respire.
- combustion of fossil fuels and wood releases CO2 back into environment and cycle starts again
What role do deritus feeders play in the carbon cycle?
- when plants, algae and animals die, animals and microorganisms feed on their remains. When these animals respire, CO2 is returned to atmosphere
- deritus feeders and microorganisms break down waste that is produced by animals
What is the carbon cycle?
Where carbon and energy is constantly being cycled from the air, through food chains, and is then returned out into the air again
How does water move from plants into the air in the water cycle?
By the process of transpiration / water is evaporated from the plants
How is compost produced?
- by decomposition
- it is decomposed organic matter (food waste) that is used as a natural fertiliser for crops and garden plants
- farmers try to provide ideal conditions for quick decay
Which microorganisms are responsible for decomposition (decay) ?
- bacteria and fungi
- deritus feeders
How does temperature affect the rate of decay?
- warmer temp increases rate of decay as it increases rate that enzymes work at
- very cold temperatures slow rate of decay
How does water availability affect rate of decay?
-decay takes place faster in moist environments because organisms need water
How does oxygen availability affect rate of decay?
-many organisms need oxygen to respire which they need to do to survive
How does the number of decay organisms affect the rate of decay?
-the more microorganisms and deritus feeders there are, the faster decomposition happens
What is biogas?
- mainly made up of methane which can be burned as fuel
- lots of different microorganisms are used to produce biogas
- they decay plant and animal waste anaerobically
How is biogas created?
- made in a simple fermenter called a digester or generator
- need to be kept at constant temperature to keep microorganisms respiring
What is the purpose of biogas generators?
They can be used to produce methane gas as a fuel
How do you calculate the rate of decay?
Rate (s-1) = 1000/ time
What can biogas be used for?
- has to be used straight away
- heating
- cooking
- lighting
- power turbine / generate electricity
What is biodiversity?
The variety of different species of organisms on Earth, or within an ecosystem
Why is high biodiversity important?
- makes sure ecosystems are stable because different species depend on each other for shelter /food
- enables human species to survive
How is human action reducing biodiversity?
- waste production
- deforestation
- global warming
How does water affect biodiversity?
- sewage and toxic chemicals from industry can pollute lakes, affecting animals and plants that rely on them for survival
- chemicals used on land can be washed into water
How does land affect biodiversity?
- toxic chemicals used for farming (pesticides and herbicides)
- bury nuclear waste underground and dump household waste in landfill sites
How does the air affect biodiversity?
-smoke and acidic gases released into the atmosphere can pollute the air
eg sulfur dioxide can cause acid rain
How is the temperature of the earth decided?
It is the balance between the energy it gets from the sun and the energy it radiates back out into space
What do greenhouse gases do?
They cause they earth to gradually heat up which causes global warming. It is a type of climate change
What happens when peat bogs are drained and peat is used as fuel?
- when peat is drained, it comes into contact with more air and some microorganisms start to decompose it
- when microorganisms respire, they use oxygen and release CO2 which contributes to global warming
- CO2 is also released when peat is burned as a fuel
Why is deforestation a problem?
- less CO2 taken in > less photosynthesis
- more CO2 in atmosphere when trees are burnt
- less biodiversity > species may become extinct due to loss of habitat
How is damage being minimised to ecosystems and biodiversity?
- breeding programmes to prevent extinction
- habitat protection
- preventing global warming-reduce level of deforestation and CO2 levels being released
- reducing waste-recycling
Who is responsible for decomposition?
- Microorganisms such as bacteria and fungi
- deritus feeders
What conditions does decomposition (decay) work best in?
Temp, water, oxygen availability, number of decay organisms
- warmer temp increases rate that enzymes in he process work at
- decay takes place faster in moist environments because organisms involved need water to carry out biological processes
- many organisms need oxygen to respire (aerobic conditions)
- the more deritus feeders and microorganisms there are, the faster decomposition happens
What are the trophic levels?
- trophic level 1- producers
- trophic level 2- primary consumers (herbivores)
- trophic level 3-secondary consumers (predators)
- trophic level 4- tertiary consumers
How does a loss of biomass at each trophic level affect the number of organisms at each level?
If there is a loss of biomass, less food will be available at each level which means that the number or organisms will decrease
What does a pyramid of biomass show?
- each bar shows relative mass of living material at trophic level
- always pyramid shaped
How do you calculate the efficiency of biomass transfer?
Biomass transferred to next level/ biomass available at previous level X 100
What is food security?
Having enough food to feed a population
How is food security being threatened?
- world population increasing quickly
- farming can be affected by new pests and pathogens or changes in environmental conditions
- high demand for foods to be imported and resources can become scarce
How can food production be made more efficient?
- limiting movement of livestock keeping them in temp controlled environment
- reduces transfer of energy from livestock to environment
- animals use less energy moving around
- more energy used for growth so more food can be produced
What is mycoprotein?
- used to make high protein meat substitutes for vegetarian meals
- fungal biomass is harvested and purified to produce mycoprotein
How do fishing quotas limit overfishing?
- prevents a certain species from being overfished
- using a bigger mesh size will let the ‘unwanted’ species escape
- young fish will slip through net so they reach breeding age
How are humans classified using the Binomial naming system?
Kingdom King Phylum Prawn Class Curry Order Or Family Fat Genus Greasy Species Sausage
