Created by ellanabishop
over 11 years ago
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Question | Answer |
why is sampling animal populations sometimes difficult? | because they are mobile and not easily visible (usually hiding from predators) |
what is one method of sampling animal populations? | capture/ recapture methord (LINCOLN INDEX) |
what are the 4 stages of the capture/recapture method? | 1.capture animals (humanely), number is counted and recorded 2.animals are marked in some way eg with waterproof paint 3.the marked animals are released for a suitable amount of time 4.a second sample is done, some are marked some are not, numbers in each group are counted again |
what is the formula for estimating the total population size in a habitat? | population size=number in first sample x number in 2nd sample(marked and unmarked / number in 2nd sample marked previously |
This method only works when there are | 1.no deaths, immigration 2.each sample is taken in exactly the same way 3. the marks given to the animal do not affect there survival rate |
what else might environmental scientists want to look at? | how species change across a habitat |
How is this done? | 1.A line (tape measure) laid down with regular intervals marked on it 2.small quadrat laid next to line and number of plants/ species is counted 3.the quadrat is moved along at regular intervals and the plant populations are recorded at each point along the line. |
how can these results be presented? | |
what is zonation? | a gradual change in the distribution of species across a habitat eg mussels or periwinkles change in number as you move from low tide up to high tide |
what is a habitat? | the part of the environment where it lives. A species becomes well suited to it's habitat and sometimes has to compete with other species for limited resources, these can be artificial or natural habitats |
what is a community? | the total number of individuals of all the different populations of organisms that live together in a habitat |
Biodiversity | A variety of different species living in a habitat |
What is an ecosystem? | a physical environment with a particular set of conditions and all the organisms that live in it are affected by the factors present in an ecosystem eg soil type, light intensity |
what is usually an ecosystems only external input? | sunlight, everything else the ecosystem supports itself on |
do natural ecosystems have a high or low biodiversity? | high |
do artificial ecosystems have a high or low biodiversity? | low because they are usually designed for a particular purpose |
what is a population? | the total number of individuals of the same species that live in a certain area |
Name 4 sampling methords | 1.pooters 2.sweepnets 3.pitfall traps 4.quadrats |
What is a pooter? advantage and disadvantage | insects sucked in through a tube, whilst you suck in the other tube. A-no harm caused to insects D-have to be methodical about sampling in order to get good results and its difficult to get idea about numbers |
what is a sweepnet? disadvantage | net used in long grass or moderately dense woodlands where there is lots of shrubs D-difficult to get true representative particularly in terms of relative number of organisms |
what is a pitfall trap? advantage and disadvantage | whole in the ground, usually filled with a yoghurt pot to catch small insects as they walk over. D-sometimes water, ethanol, detergent can get into bottom and kill animals A-if enough is used it can give a good representative sample |
What is a quadrat? advantage | square frame, A-excellent results if placed randomly, population of species can be estimated |
Name the photosynthesis word equation | carbon dioxide+water---->glucose+oxygen |
say the photosynthesis balanced symbol equation... | 6CO2+6H20----->C6 H12 O6+6O2 |
Name 4 things glucose can be converted into | 1.starch 2.cellulose 3.nitrates+other nutrients in proteins 4.Lipids(fats or oils) to store in seeds |
What is respiration the opposite to? | Photosynthesis |
Name the word equation for respiration? | glucose+oxygen---->carbon dioxide+water |
When to plants respire? | continuously |
What are the 3 factors that affect the rate of photosynthesis? | 1.temperature 2.light intensity 3.carbon dioxide concentration |
At what temperature do the enzymes controlling photosynthesis start to be destroyed and the rate of photosynthesis declines to zero? | 45 oC |
When the light intensity reaches a certain point.... | it no longer has an effect meaning it is not the limiting factor |
when the carbon dioxide concentration reaches a certain point... | the rise in carbon dioxide levels now has no effect meaning carbon dioxide is no longer the limiting factor |
why is starch a very useful storage molecule? | because it's insoluble |
Why does plant growth slow down in winter? | due to lack of sunlight and warmth |
The rate of photosynthesis in a plant can be increased in winter by | ARTIFICIAL GREENHOUSES |
name 3 things artificial greenhouses are good for? | 1.temperature increased by heaters 2.light intensity increased by lamps 3.carbon dioxide concentration increased by chemicals or as by product of the fossil fuel heaters |
What is Diffusion? | The transportation of substances from an area of high concentration to an area of low concentration > |
what controls what substances leave and enter the cell in diffusion? | The cell membrane |
Name 4 things living cells need to obtain? | 1.oxygen 2.glucose 3.water 4.minerals |
an example of a waste product a cell doesn't need? | carbon dioxide |
3 ways the rate of diffusion is increased... | 1.the cell membranes surface area is bigger 2.there is a bigger difference between concentrations 3.the particles have a shorter distance to travel |
What is osmosis? | The diffusion of water from a dilute solution to a more concentrated solution through a partially permeable membrane < |
What is a partially permeable membrane? | a membrane that only allows certain molecules or atoms through, graded by size |
why don't the cell walls affect the movement of water in osmosis? | because they are freely permeable |
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