ecosystems Flashcards

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1
Q

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.

A

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 ;

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2
Q

Outline how the percentage efficiency of energy transfer between producers and herbivores can be estimated.

A

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;

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3
Q

Describe the differences between the following biological terms:
a pioneer community and a climax community

A

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

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4
Q

Describe the differences between the following biological terms:
decomposition and denitrification

A

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 ;

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5
Q

Describe the differences between the following biological terms:
conservation and preservation

A

1 conservation maintains , ecosystem / biodiversity /
species / habitats
or
conservation involves , active / sustainable ,
management of , ecosystem / resource / habitat ;
2 preservation leaves , ecosystems / habitats ,
undisturbed ;

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6
Q

Suggest three ways that farmers can maximise the efficiency of the transfer of energy up food chains from primary consumers to humans.

A

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 ;

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7
Q

Comment on what the different arrangements of plants in the Oxford Botanic Garden over time tell us about the nature of scientific knowledge.

A

idea of tentative / uncertain / developing / advancing /

improving / dynamic ;

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8
Q

Suggest two purposes of a plant collection in a modern botanic garden.

A

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 ;

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9
Q

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?

A

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 ;

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10
Q

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.

A

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 ;

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11
Q

Give two reasons why both plants and animals need to be able to respond to changes in their environment.

A

(both) to, avoid / counter, (abiotic) stress ;
(both) to avoid, being eaten / predation ;
(both) to access resources ;

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12
Q

Outline the role of decomposers in the decomposition of leaves.

A
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
\+
;
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13
Q

Define the following terms:
producer
consumer
rophic level

A

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 ;

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14
Q

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.

A

decomposers / named decomposers, not, present / active ;
waterlogging reduces, air / oxygen ;
acidity / low pH , stops (decay) enzymes working ;

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15
Q

Explain why two areas of the same size were monitored.

A
two areas
as a control / for comparison / to see the effect of removal of
starfish ;
same size
to make test, valid / fair / unbiased ;
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16
Q

the nature of scientific knowledge and the role of the scientific community in validating new knowledge.

A

knowledge , tentative / uncertain / subject to change ;

to re-test / check, hypotheses / results ;

17
Q

the study of the interactions between organisms and their environment

A

ecology

18
Q

the physical (non-living) factors in the environment

A

abiotic

19
Q

a physical area that includes all the organisms present and their interactions with each other and with the physical environment.

A

ecosystem

20
Q

The distribution and abundance of plants in a habitat can show how a physical factor varies across the habitat.
Describe how you would measure the distribution and abundance of plants over a distance of 100 metres.

A
1 tape measure / rope, laid ;
2 line / belt, transect ;
3 continuous / interrupted / AW ;
4 (use quadrat to) record percentage cover of plants ;
5 (use quadrat with) ACFOR scale ;
6 point quadrat use described ;
7 use of key to identify species ;
8 data recording sheets prepared in advance ;
21
Q

Briefly describe the steps that must occur for plant protein to be converted to animal protein

A

1 (sheep / animals) ingest / consume / eat / feed on
(grass / plants) ;
2 digest / hydrolyse , (protein) to amino acids ;
3 amino acids move into , blood / cells ;
4 synthesis of proteins / translation ;

22
Q

Name the bacteria that carry out processes nitrification and explain the significance of these bacteria for the growth of plants.

A

1 C is Nitrosomonas ;
2 D is Nitrobacter ;
3 C and D are nitrifying bacteria ;
for mps 1 , 2 and 3 internal max 2
4 plants need nitrates to make ,
amino acids / protein(s) / enzymes / DNA / RNA /
nucleic acids / chlorophyll / cytoplasm / new cells ;

23
Q

Suggest a crop she could plant that would allow process nitrogen fixation to occur and explain how this would add nitrate to the soil.

A

1 legume / any named leguminous plant ;
2 Rhizobium / nitrogen-fixing bacteria (in root nodules) ;
3 idea of converting nitrogen gas / N2 , into ,
compounds / ammonium / ammonia /
amino acids / protein (in plants) ;
4 plants ploughed in / plants left to decay

24
Q

Three suggested methods to reduce the effect of hedgehogs on the numbers of waders in area 2 were considered. These were:• trapping and moving hedgehogs to the mainland• trapping hedgehogs and keeping them in captivity indefinitely• trapping of hedgehogs followed by humane killing.The third method was judged to be the most effective and likely to succeed in reducing hedgehog numbers.Comment on the ethical issues involved in making this decision.

A

idea that the following may be ethically wrong
1 killing hedgehogs ;
2 letting hedgehogs , kill / decrease number of , waders ;
3 introducing hedgehogs to island (upset the ecosystem) ;
4 catching / moving , hedgehogs might cause suffering ;
5 doing nothing ;

25
Q

Suggest a suitable technique by which the student might have collected his samples of ladybirds along this transect.

A

1 sweep netting / sweep vegetation with a net ;
2 beating / beat trees and bushes ;
3 pooter / pooting / described ;

26
Q

The student’s teacher suggested he should make several transects up the hill rather than just one transect. Explain why this is good experimental design.

A

idea of ladybirds not evenly distributed /
some parts of hill different /
more representative ;
lets reliability be assessed / anomalies identified ;

27
Q

Suggest a method of processing this data to make comparisons between the frequency of the red form and black form of ladybird at the different altitudes more valid.

A
M1 (calculate) % / proportion / ratio ;
E1 as different total numbers at each site ;
or
M2 (draw) bar chart / kite diagram ;
E2 pictorial data easier to understand ;
28
Q

Discuss possible reasons for the differences in net primary production in these ecosystems.

A

climate - tropical versus temperate
tropical has …
higher temperature / hotter ;
more (sun)light / days longer ;
photosynthesis faster ;
idea that
more storage of , organic molecules / biomass / energy
or
more formation of , organic molecules / biomass ;
AVP ;
vegetation - woodland or rainforest versus grassland(s)
woodland or forest has …
idea of greater complexity / greater biodiversity /
more niches ;
competition for space less limiting ;

29
Q

Outline how the energy content, in kJ, of a primary producer such as grass can be measured in the laboratory.

A

(bomb) calorimeter ;
detail of technique ;
detail of , measurement / analysis ;