ecosystems Flashcards
The recorded number of elk legally shot by hunters provides accurate data.Suggest why these data are accurate, but the method used to obtain these data is not a valid way of estimating the number of elk in the population.
accurate because
idea that actual number of elk shot is recorded ;
method not valid because
idea that number of elk shot / hunting success ,
varies independently of population size ;
Outline how the percentage efficiency of energy transfer between producers and herbivores can be estimated.
1
herbivore / primary consumer,energy x 100 ;
producer energy
Plus any 3 of the following:
2 (a sample of) producers collected ;
3 (a sample of) herbivores /primary consumers
collected;
4 (collected from) the same area ;
5 (measure) biomass / dry mass (of individual or
population) ;
6 energy content calculated of producer and
herbivore ;
7 use of calorimeter / described;
Describe the differences between the following biological terms:
a pioneer community and a climax community
1 pioneers arrive , before climax / earlier ; ora
2 pioneer communities subject to , greater / more ,
change / succession / replacement ; ora
3 pioneer community (usually) has , less / lower ,
biodiversity ; ora
4 idea that pioneer community is (often) less ,
stable / self-sustaining ; ora
5 pioneer community has lower biomass ; ora
Describe the differences between the following biological terms:
decomposition and denitrification
1 decomposition is break down ,
dead matter / waste
or
decomposition is conversion of
organic matter to inorganic ;
2 denitrification is conversion of nitrates to nitrogen (gas) ;
3 decomposition increases , mineral / nitrate , supply
and
denitrification reduces , mineral / nitrate , supply ;
Describe the differences between the following biological terms:
conservation and preservation
1 conservation maintains , ecosystem / biodiversity /
species / habitats
or
conservation involves , active / sustainable ,
management of , ecosystem / resource / habitat ;
2 preservation leaves , ecosystems / habitats ,
undisturbed ;
Suggest three ways that farmers can maximise the efficiency of the transfer of energy up food chains from primary consumers to humans.
animals = primary consumers
1 keep animals, warm / indoors ;
2 reduce animal movement ;
3 feed animals high, protein / energy, food ;
4 vaccination / (routine) antibiotics, for animals ;
5 selective breeding / genetic engineering,
for improved animals ;
6 slaughter just before, mature / full size ;
Comment on what the different arrangements of plants in the Oxford Botanic Garden over time tell us about the nature of scientific knowledge.
idea of tentative / uncertain / developing / advancing /
improving / dynamic ;
Suggest two purposes of a plant collection in a modern botanic garden.
1 conservation / keep rare plants / save endangered plants ;
2 gene bank OR genetic resource / store of alleles ;
3 teaching / education ;
4 leisure / amenity / visitor attraction / aesthetic value ;
DNA sequence information is most useful when used with the phylogenetic (cladistic) approach to classification.How does the phylogenetic approach to classifying species differ from the biological species concept?
phylogenetic approach
no need to test for interbreeding ;
ref. common ancestor / monophyletic groups ;
can apply to organisms that reproduce asexually ;
can apply to, extinct organisms / fossils ;
Dog fleas are small parasitic insects that live in the fur of dogs and feed on their blood. Dogs are routinely treated with sprays or powders to kill fleas.A vet believes that dog fleas may have become resistant to a popular flea-killer product.
He asks an A-level work experience student to plan an experiment to test this hypothesis. The student needs to sample fleas from dogs visiting the surgery and also fleas from long grass in fields visited by dog-walkers. The fleas then need to be tested for resistance to the flea-killer.Describe the methods the student could use to:
• collect both samples of fleas
• find out the proportion of fleas that are resistant
• process the data.
collection
1. named equipment for collecting from, dogs / fields ;
2. get, large number / over 100 (fleas) ;
3. use several, dogs / fields ;
4. idea of random sampling (dogs / field) ;
testing
5. (named) container ;
6. correct dose / range (of concentrations), tested ;
7. control without flea killer ;
8. delivery method described ;
processing
9. leave for set time ;
10. count number of, dead / live, fleas (after testing) ;
11. calculate percentage (frequency) of, alive / dead /
resistant / non-resistant ;
Give two reasons why both plants and animals need to be able to respond to changes in their environment.
(both) to, avoid / counter, (abiotic) stress ;
(both) to avoid, being eaten / predation ;
(both) to access resources ;
Outline the role of decomposers in the decomposition of leaves.
1 bacteria / fungi ; 2 idea of external digestion ; 3 by , enzymes / named enzymes ; 4 absorption of breakdown products ; 5 release of carbon dioxide and water ; 6 (breakdown of protein) makes , ammonium , ions / compounds or NH4 \+ ;
Define the following terms:
producer
consumer
rophic level
producer
(leaves / plants) fix carbon / photosynthesise /
make food / autotroph(ic) /
convert light energy to chemical energy /
convert inorganic, C / CO2, to organic molecules ;
consumer
(bird) eat / derives energy from / feeds on ,
other organisms
or
heterotroph(ic) ;
trophic level
stage / position / place / level , in a food , chain / web ;
In Ireland in 2002, two well-preserved Iron Age human bodies were found in peat bogs. Despite having been dead for over two thousand years, the bodies had not decomposed. They still had skin, hair and muscle.
Suggest why these bodies had not decomposed.
decomposers / named decomposers, not, present / active ;
waterlogging reduces, air / oxygen ;
acidity / low pH , stops (decay) enzymes working ;
Explain why two areas of the same size were monitored.
two areas as a control / for comparison / to see the effect of removal of starfish ; same size to make test, valid / fair / unbiased ;