b7 Flashcards
define habitat
The environment in which an organism lives.
define population
The total number of organisms of the same species living in the same geographical area.
define community
The populations of all the different species that live in the same habitat.
define biotic
Living parts of the environment.
define abiotic
Non-living parts of the environment.
define ecosystem
Both biotic and abiotic parts of an environment and how they interact.
what do plants compete for?
- Light
- Space
- Water
- Minerals in soil
what do animals compete for?
- Food
- Water
- Mating Partners
- Territory
what is interdependence?
- all species depend on other species in some way.
what is meant by a stable community?
- the populations of organisms are in balance with each other and with abiotic resources like water.
name four biotic factors
- Availability of food
- Arrival of a new predator
- Competition
- New pathogens
name six abiotic factors
- Light Intensity
- Temperature
- Water
- PH and mineral content of the soil
- Wind Intensity and Direction
- Carbon dioxide and Oxygen
how are camels adapted to their environment?
- Leathery Mouth = they can chew desert plants, which often have thorns
- Long Eyelashes = keep dust out of their eyes
- Hump = stores most fat here, allows heat loss from other parts of the body and reduces water loss from sweating.
- Wide Feet = prevent the camel from sinking into the sand
how are arctic foxes adapted to their environment?
- Very small ears = reduces the surface area of the fox 🡪 reduces heat loss
- Very thick fur = provides insulation and reduces heat loss to the air
- Fur on the soles of the feet = reduces heat loss to the ice and the snow
- White fur coat = effective camouflage which helps it hunt its prey
how is a cactus adapted to its environment?
- Small leaves = reduces water loss
- Spines = protect cactus from animals
- Stores water in its stem = can survive months without rain
name the food chain in order
- producer
- primary consumer
- secondary customer
- tertiary consumer
what is a predator?
- consumers that kill and eat each other
what is a prey?
- the animal that is being eaten
what are the two types of sampling?
- random sampling
- sampling along a transect
what is a quadrat?
- a square with lots of different squares in it.
when do you carry out random sampling?
- when comparing the numbers of organisms in different areas.
what is the equation you need to use to calculate population size?
total population size = total area/area sampled X number of organisms of that species counted in the sample.
how do you carry out random sampling?
- split the area of the field with the most light intensity.
- use a random name generator to get the co-ordinates.
- place the quadrat at those co-ordinates and count the dandelions.
- repeat this for 10 co-ordinates.
- calculate the mean and repeat these steps for the darker side.
when do we use sampling along a transect?
- when investigating whether the number of species change as we move across a habitat.
what is a transect?
- a line such as a tape measure or a piece of rope.
how do you carry out sampling along a transect?
- place the tape measure along the area you want to sample.
- place a quadrat on your selected area and count the number of dandelions.
- move the quadrat along the transect at a set distance.
- repeat these steps until you have reached the end of the transect.
- lastly, calculate the mean.
how do you calculate mean?
- add all the values together and divide by how many answers there are.
how do you calculate median?
- select the middle number by ordering them from lowest to highest
how do you calculate mode?
- look for the number which appears the most
describe the carbon cycle
- Carbon enters the atmosphere as carbon dioxide from respiration and combustion.
- Producers absorb carbon dioxide to make glucose in photosynthesis.
Animals feed on the plant passing the carbon compounds along the food chain. - Most of the carbon they consume is exhaled as carbon dioxide that is formed during aerobic respiration. The animals and plants eventually die.
- Decomposers break down the dead organisms and return the carbon in their bodies to the atmosphere as carbon dioxide by respiration. In some conditions, decomposition is blocked.
- The plant and animal material may then be available as fossil fuel in the future for combustion.
how do you calculate range?
biggest number - smallest number
how do plants and animals use and release water?
- plants use water during photosynthesis, whereas animals use water during respiration.
describe the water cycle
- Almost all the water on Earth is found in the oceans. This is salt water.
- Energy from the sun causes water to evaporate from the surface of the sea.
- Water vapour travels in the air and cools down.
- Once cooled, water vapour condenses to form clouds.
- The water in clouds falls to the ground as precipitation (rain, snow, sleet and hail) = fresh water.
- Once the water hits the ground some of it evaporates back into the atmosphere as water vapour.
- Some of the water passes through rocks and forms ACQUIFIERS.
- A lot of water forms rivers and streams that eventually drain back to the sea.
what is biodiversity?
- the variety of all the different species of organisms on Earth.
why is biodiversity important?
- it is important for ecosystems, as species depend on each other for food and shelter
- a high level of biodiversity makes the ecosystem more stable
- many medicinal drugs come from the species
explain how waste management impacts biodiversity
- Water Pollution: Sewage and Fertilisers
- humans produce a large amount of sewage
- this contains both urine and faeces.
- water can also be polluted with fertilisers from farms
- both fertilisers and untreated sewage cause
dissolved oxygen levels to fall, and this can kill
aquatic organisms - Factories
- toxic chemicals are released into rivers from
factories.
- these can kill animals in rivers. - Landfills
- millions of tons of waste are dumped in
landfills.
- landfills destroy habitats for plants and
animals.
- toxic chemicals can also leach out of landfills
and pollute the soil.
explain how land use impacts biodiversity
- Peat:
- peat bogs and peat lands contain large amounts of dead plant materials.
- conditions in the peat mean that decay is very slow.
- this means they contain a large amount of trapped carbon.
- however, these habitats are being destroyed, reducing biodiversity.
- peat is used to produce cheap compost for gardens and farms and it is burned to generate energy for electricity.
what are peat bogs?
- they contain large amounts of dead plant materials and contain a lot of trapped carbon.
what is peat being used for?
- to produce cheap compost
- it is also burnt to generate energy for electricity
how does destroying peat reduce biodiversity?
- it reduces the area of habitat
- so animals, plants and micro organisms have nowhere to live
what are the problems with peat?
- once it is extracted, it begins to decay and releases CO2
- a lot of peat is burnt and releases CO2 again
- many gardeners stop buying compost with peat
what causes global warming?
- increased temperature of the Earth caused by humans
name three greenhouse gases
- carbon dioxide
- methane
- water vapour
name three consequences of global warming
- loss of habitat
- migration patterns of animals might change
- early flowering of plants
state four ways we can reduce the negative effects of humans on biodiversity
- breeding programmes for endangered species
- protecting habitats
- farmer
- governments
