What is a habitat?
The place where an organism lives.
Define a population.
All the organisms in one species, living in a habitat.
What is a community?
All the populations of different species in a habitat.
What is an environment?
The conditions surrounding an organism.
Define an ecosystem.
The interaction of a community of living organisms with the abiotic parts of their environment.
What 6 resources do plants compete for?
-light -space -water -mineral ions from the soil -seed dispersers -pollinators
What 4 resources do animals compete for?
-territory/shelter -water -food -mates
What is interdependence?
Species in a community depending on other species for things such as food, shelter, pollination and seed dispersal.
What is the term for species in a community depending on other species for things such as food, shelter, pollination and seed dispersal?
What can interdependence mean when there is a change in an ecosystem?
It can have far-reaching effects.`
What are the 5 kingdoms of organisms?
-Prokaryotes -Plants -Animals -Fungi -Protocista
What are abiotic factors?
Non-living factors which affect organisms, e.g. temperature.
What are biotic factors?
Living factors which affect organisms. e.g. food.
Name 7 abiotic factors.
- Moisture level
- Light intensity
- Wind intensity and direction
- Soil pH and mineral content
- Carbon dioxide levels (plants)
- Oxygen level (aquatic organisms)
Name 4 biotic factors.
- New predators
- Availability of food
- New pathogens
What is a stable community?
One where the populations don't fluctuate very much; they are in balance.
What are the three types of adaptation?
Structural (features of an organisms body structure e.g. colour, shape)
Functional (internal chemical reactions) e.g. things to do with reproduction and metabolism. Desert animals conserve water by producing very little sweat and small amounts of concentrated urine.
How are camels adapted to live in hot conditions?
-Long eyelashes -Thin layer of fat -Humps of fat that can be broken down into water -Double eyelids -Large surface area to volume ratio
How are animals that live in cold conditions adapted to their environment?
-Thick layer of blubber for insulation -Low surface area to volume ratio
How are arctic animals adapted to their environment?
- White fur to camouflage against the snow
- Helps them sneak up on prey/hide from prey.
Give an example of a behavioral adaptation.
Swallows migrating to warmer climates during the winter to avoid the problems of living in cold conditions.
Some microorganisms are adapted to live in very extreme conditions. What are these called?
Give examples of 3 conditions extremophiles can live in.
- High temperatures (volcanic vents)
- High salt concentration ( very salty lakes)
- High pressure ( deep sea vents)
What are secondary consumers eaten by?
Explain this graph:
What is a producer?
- At the start of the food chain.
- They make their own food using the energy from the sun.
- Usually green plants or algae
- They make glucose by photosynthesis
When a green plant produces glucose, what can some of it be used to make?
Other biological molecules in the plant which is the plants biomass ( the mass of a living material).
Biomass can be thought of as........
Energy stored in a plant.
How is energy transferred through living organisms in an ecosystem?
When organisms eat other organsims.
What are primary consumers eaten by?
The population of any species is usually limited by?
The amount of food available.
What happens if the population of the prey increases?
The population of preditors will increase.
What happens if the population of predators increases?
The population of prey decreases.
The water cycle (8)
- Energy from the sun makes water evaporate from the land and sea, turning it into water vapour.
- Water also exaporates from plants- known as transpiration.
- The warm water is carried upwards, when it gets higher up, it cools and condenses to form clouds.
- Water falls from the clouds as precipitation (usually rain or snow and hail) onto land, providing fresh water for plants and animals.
- Some water is absorbed by soil and taken up by plant roots, providing fresh water for photosynthesis. Some water becomes part of the plants tissues and is passed along to animals in food chains.
- Animals need water for chemical reactions that occur in their bodies. Animals return water to the soil and atmosphere through excretion ( processes getting rid of waste products e.g. sweating and urination).
- Water that doesn't get absorbed by the soil will runoff into streams and rivers.
- The water then drains back into the sea before it evaporates all over again.
Why are predator- prey cycles always out of phase?
It takes a while for one population to respond to changes in the other population.
Where an organism is found is affected by what?
What is quantitative data?
Measures of values or counts that are expressed as numbers.
What are the ways to study the distribution of an organism?
- Measure how common an organism is in two sample areas (e.g. using quadrats) and compare them.
- Study how the distribution changes across an area, e.g. by placing quadrats along a transect.
What is a quadrat?
A quadrat is a square frame enclosing a known area, e.g. 1m2.
Write in steps how you would compare how common an organism is in two sample areas e.g. shady and sunny spots.
- Place a 1m2 quadrat on the ground at a random point within the first sample area. (E.g. divide the area into a grid and use a random number generator to pick coordinates.
- Count all the organisms within the quadrat.
- Repeat steps one and two as many times as you can.
- Work out the mean number of organisms per quadrat within the first sample area.
- Repeat steps 1-4 in the second sample area.
- Finally compare the two means. (E.g. you might find 2 daises per m2 in the shade and 22 daises per m2 (lots more) in the open field.)
How do you work out the mean number of organisms per quadrat ?
Mean = Total number of organisms / Number of quadrats
How do you work out the population size of an Organism in One Area?
E.g. Students used 0.5m2 quadrats to randomly sample daises on an open field. The students found a mean of 10.5 daises per quadrat. The field had an area of 800m2. Estimate the population of daises on the field.
- Work out the mean number of organisms per m2.
- Then multiply the mean by the total area (in m2) of the habitat.
- 1 / o.5 = 2 2 * 10.5 = 21 daises per m2.
- 800 * 21 = 16,800 daises on the open field.
When do you use transects ?
To study the distribution of organisms along a line.
Write bullet points on how you would use a transect.
- Mark out a line in the area you want to study using a tape measure.
- Then collect the data along the line.
- You can do this by just counting all the organisms you're interested in that touch the line.
- Or you can collect data by using quadrats. These can be placed next to each other along the line or at intervals, for example every 2m.
What is the temperature of the earth balanced between?
The energy it gets from the Sun and the energy it radiates back into space.
What do gases in the atmosphere act like?
What do they do?
Does it increase/ decrease the temperature of the planet?
An insulating layer.
They absorb most of the energy that would normally be radiated out into space , and re-radiate it in all directions (including back towards the Earth).
This increases the temperature of the planet.
If gases didn't act as an insulating layer around the Earth, what would happen?
If this didn't happen, at night there would be nothing to keep any energy in and we would get very cold.
What are the several different gases in the atmosphere called that help keep the energy in?
Are these gases increasing/ decreasing?
- Greenhouse gases and the main ones are carbon dioxide ( CO2) and methane.
- The levels of these gases are rising quite sharply.
Why is the Earth gradually heating up?
What term is it called?
What is it a type of and can cause?
- Due to the increasing levels of greenhouse gases.
- This is called Global Warming.
- It is a type of Climate Change and causes other types of climate change e.g. changing rainfall patterns.
What are some of the consequences of Global Warming?
- High temperatures: cause seawater to expand and ice caps to melt. Causing sea levels to rise, bad for people/ animals living in low-lying places.
- Flooding = loss in habitats.
- The distribution of of many wild animal and plant species may change as temperatures increase and the amount of rainfall changes in difference areas.
- There may be changes in migration patterns.
- Biodiversity could be reduced if some species are unable to survive a change in the climate so become extinct.
What purposes can humans use land for?
This means that theres less land for what?
Building, quarrying, farming and dumping waste.
What do humans do that can have a bad effect on the environment?
- Destruction of habitats like peat bogs and other areas of peat.
What is deforestation?
When can it cause problems?
- It's the cutting down of forests.
- This causes problems when it's done large scale, such as chopping down rainforests in tropical areas.
Why does deforestation occur?
- To clear land for farming (e.g. cattle or rice crops) to provide more food.
- To grow crops from which biofuels based on ethanol can be produced.
Deforestation can cause many problems, what are the main three?
- There is less carbon dioxide taken in.
- There is more carbon dioxide in the atmosphere.
- There is less biodiversity.
Deforestation = less carbon dioxide taken in. WHY?
- Cutting down lots of trees means that the amount of carbon dioxide removed from the atmosphere during photosynthesis is reduced.
- The trees "lock up" some of the carbon they absorb during photosynthesis in their wood which can remove it from the atmosphere for hundreds of years. Removing trees= less CO2 "locked up".
Deforestation = more carbon dioxide in the atmosphere. WHY????
- Carbon dioxide is released when trees are burnt to clear land. ( Carbon in wood doesn't contribute to atmospheric pollution until it's released by burning.)
- Microorganisms feeding on bits of dead wood release carbon dioxide as a waste product of respiration.
Deforestation = Less biodiversity WHY?
- What is Biodiversity
- Biodiversity is the variety of different species- the more species, the greater the biodiversity.
- Habitats like forests can contain a huge number of different species of plants and animals, so when they are destroyed there is a danger of many species becoming extinct- biodiversity it reduced!!!!
- What are bogs?
- Why don't plants that live there fully decay?
- What do the plants build up to form?
- They are areas of land that are acidic and waterlogged.
- There's not enough oxygen.
- The partly-rotted plants gradually form up to build peat.
Where in the plants is carbon stored instead of being released into the atmosphere?
Why peat bogs often drained?
- So that the area can be used as farmland.
- Peat is cut up and dried to use as fuel.
- Its also sold to gardeners as compost.
Does peat grow faster or slower than it is being used up?
Being used faster than it forms.
When peat is drained, what does it come into contact with?
- It comes into more contact with air and some microorganisms start to decompose it.
- When there microorganisms respire, they use oxygen and release carbon dioxide, contributing to global warming.
What is released when peat is burned as a fuel?
Destroying bogs also destroys what?
It destroys/ reduces the area of the habitats of some of the animals, plants and microorganisms that live there so it reduces biodiversity.
It's important that biodiversity is maintained at a high enough level to make sure ecosystems are stable.
Give examples of programmes that concerned citizens have set up to minimise damge by human activity.
- Breeding programmes- help prevent endangered species from becoming extinct. Animals are bred in captivity to make sure the species survives if it dies in the wild. Individuals can be sent into the wild to boost or re-establish a population.
- Programmes to protect and regenerate rare habitats like mangroves, heathland and coral reefs have been started. Protecting habitats = protecting species and preserving the ecosystem and biodiversity in the area.
- Programmes to reintroduce hedgerows and field margins around fields on farms where only one type of crop is grown.
- Some governments have introduces regulations and programmes to reduce the level of deforestation taking place.
- People are encoruaged to recycle to reduce the amount of waste that gets dumped in the landfill, which could reduce the amount of land taken over for landfill, leaving ecosystems in place.
What are the conflicting pressures that can affect how biodiversity is maintained?
Protecting biodiversity costs money
- Governments sometimes pay farmers a subsidy to reintroduce hedgerows and field margins to their land.
- Cost money to keep watch on whether the programmes and regulations designed to maintain biodiversity are being followed.
- There can be conflict between protecting biodiversity and saving money.
Conflicting pressures affecting