1. Nitrogen cycles through ecosystems via organic compounds, ammonium, nitrites, and nitrates due to the actions of saprophytic bacteria and nitrifying bacteria. Nitrogen-fixing bacteria in root nodules of legumes convert nitrogen to organic compounds that fertilize the plant.
2. Decomposer bacteria release ammonia and nitrifying bacteria convert it to nitrites and nitrates via nitrification. There is competition between microbes for these nitrogen sources.
3. The document outlines scientific marking schemes for content, breadth, relevance, presentation, and use of technical vocabulary. It provides example questions and marking schemes related to ecology, biogeochemical cycles, microbes, and earthworm
1. Organic nitrogen is converted to ammonium compounds by decomposers and then to nitrates by nitrifying bacteria for uptake by plant roots. Nitrogen-fixing bacteria convert nitrogen to compounds used by legumes, reducing the need for fertilizer. Shorter food chains produce greater fish yields due to less energy loss between trophic levels.
2. Random quadrats are used to sample plant diversity. Heather affects diversity by providing habitat. Nitrogen is used for non-photosynthetic plant parts and eaten by grouse. Younger plants are more productive. Enzymes are proteins that catalyze reactions without being used up.
3. Earthworm taxonomy is given. Enzymes are not
1. Energy transfer from forests is disrupted when trees are removed, impacting soil stability, carbon dioxide levels, biodiversity, and rainfall patterns. Deforestation harms local ecosystems.
2. Chemical insecticides accumulate in ladybird bodies through eating greenflies and cannot be excreted, increasing their numbers. Biological control using ladybirds is more stable as numbers fluctuate less with seasons and plants.
3. Two plant species interact through competing for limited resources like light or nutrients. Heather provides nitrogen fixing bacteria that stimulates spruce growth while inhibiting heather.
This document discusses several topics related to agriculture and ecology:
1. Deforestation can lead to soil erosion, increased carbon dioxide levels, and loss of biodiversity.
2. Using chemical versus biological pest control methods: chemicals fluctuate over time but biological controls are more constant; chemicals may not reach all plants.
3. Interspecific competition was shown between spruce and heather over light and nutrients; spruce grows better when heather is controlled.
4. Speciation occurs when populations become isolated and develop differences over time due to varying environments and natural selection, allowing them to breed but not mix ecologically. Increased diversity supports more niches and food sources.
5. Beach
This document describes a system designed to meet the basic needs of a family of four living in the tropics. The system includes crop plants, solid and liquid waste, cattle, chickens, algae in a shallow pond, and fish. Urine, feces, and crop waste are recycled through various processes involving bacteria, plants, and animals to provide nutrients to crops and meet other needs in a sustainable cycle.
This document contains information about nitrogen cycling in soil and forests. It discusses:
1. The roles of decomposers and nitrifying bacteria in breaking down organic matter and converting ammonia to nitrates.
2. How burning forests releases more carbon dioxide into the atmosphere since trees are no longer removing carbon through photosynthesis.
3. Various factors that allow hardwood trees to regenerate more easily than softwoods in areas where forests have been cleared, such as competition for light, temperature and moisture regulation, and nutrient recycling.
1. Students are responsible for completing tasks in their assigned chamber, which include measuring dry mass of materials, counting organisms, and following other instructions.
2. Data that can be graphed includes growth of plants, pH and temperature levels, and water volume.
3. Students will analyze their observations and relate them to the 4 Laws of Ecology. They will create a video journal summarizing their experiment and a diary with data tables/graphs over a 5 day period.
1. The document describes a system designed to meet the basic needs of a family of four living in the tropics. The system generates fuel gas from bacterial fermentation of urine and feces. It uses solid waste from the fermenter as fertilizer for crops and stocks the pond with fish that feed on algae rather than carnivorous fish.
2. The document discusses student responses to questions about the nitrogen cycle and leguminous plants. It notes confusion between nitrogen fixing and denitrifying bacteria. It also notes that students have difficulty with the sequence of changes in the nitrogen cycle and defining nitrogen compounds.
3. The document evaluates student essays on relationships between animals and plants. It finds the scientific
1. The document describes a system designed to meet the basic needs of a family of four living in the tropics. The system generates fuel gas from bacterial fermentation of urine and feces. It uses solid waste from the fermenter as fertilizer and grows leguminous plants such as beans and peanuts. Fish that feed on algae are stocked in the pond rather than carnivorous fish.
2. Candidates were asked questions about various parts of the system. For example, how the nitrogen cycle makes nitrogen in urine and feces available to plants, the advantages of growing legumes, and the benefits of stocking the pond with algae-feeding fish rather than carnivorous fish.
1. Organic nitrogen is converted to ammonium compounds by decomposers and then to nitrates by nitrifying bacteria for uptake by plant roots. Nitrogen-fixing bacteria convert nitrogen to compounds used by legumes, reducing the need for fertilizer. Shorter food chains produce greater fish yields due to less energy loss between trophic levels.
2. Random quadrats are used to sample plant diversity. Heather affects diversity by providing habitat. Nitrogen is used for non-photosynthetic plant parts and eaten by grouse. Younger plants are more productive. Enzymes are proteins that catalyze reactions without being used up.
3. Earthworm taxonomy is given. Enzymes are not
1. Energy transfer from forests is disrupted when trees are removed, impacting soil stability, carbon dioxide levels, biodiversity, and rainfall patterns. Deforestation harms local ecosystems.
2. Chemical insecticides accumulate in ladybird bodies through eating greenflies and cannot be excreted, increasing their numbers. Biological control using ladybirds is more stable as numbers fluctuate less with seasons and plants.
3. Two plant species interact through competing for limited resources like light or nutrients. Heather provides nitrogen fixing bacteria that stimulates spruce growth while inhibiting heather.
This document discusses several topics related to agriculture and ecology:
1. Deforestation can lead to soil erosion, increased carbon dioxide levels, and loss of biodiversity.
2. Using chemical versus biological pest control methods: chemicals fluctuate over time but biological controls are more constant; chemicals may not reach all plants.
3. Interspecific competition was shown between spruce and heather over light and nutrients; spruce grows better when heather is controlled.
4. Speciation occurs when populations become isolated and develop differences over time due to varying environments and natural selection, allowing them to breed but not mix ecologically. Increased diversity supports more niches and food sources.
5. Beach
This document describes a system designed to meet the basic needs of a family of four living in the tropics. The system includes crop plants, solid and liquid waste, cattle, chickens, algae in a shallow pond, and fish. Urine, feces, and crop waste are recycled through various processes involving bacteria, plants, and animals to provide nutrients to crops and meet other needs in a sustainable cycle.
This document contains information about nitrogen cycling in soil and forests. It discusses:
1. The roles of decomposers and nitrifying bacteria in breaking down organic matter and converting ammonia to nitrates.
2. How burning forests releases more carbon dioxide into the atmosphere since trees are no longer removing carbon through photosynthesis.
3. Various factors that allow hardwood trees to regenerate more easily than softwoods in areas where forests have been cleared, such as competition for light, temperature and moisture regulation, and nutrient recycling.
1. Students are responsible for completing tasks in their assigned chamber, which include measuring dry mass of materials, counting organisms, and following other instructions.
2. Data that can be graphed includes growth of plants, pH and temperature levels, and water volume.
3. Students will analyze their observations and relate them to the 4 Laws of Ecology. They will create a video journal summarizing their experiment and a diary with data tables/graphs over a 5 day period.
1. The document describes a system designed to meet the basic needs of a family of four living in the tropics. The system generates fuel gas from bacterial fermentation of urine and feces. It uses solid waste from the fermenter as fertilizer for crops and stocks the pond with fish that feed on algae rather than carnivorous fish.
2. The document discusses student responses to questions about the nitrogen cycle and leguminous plants. It notes confusion between nitrogen fixing and denitrifying bacteria. It also notes that students have difficulty with the sequence of changes in the nitrogen cycle and defining nitrogen compounds.
3. The document evaluates student essays on relationships between animals and plants. It finds the scientific
1. The document describes a system designed to meet the basic needs of a family of four living in the tropics. The system generates fuel gas from bacterial fermentation of urine and feces. It uses solid waste from the fermenter as fertilizer and grows leguminous plants such as beans and peanuts. Fish that feed on algae are stocked in the pond rather than carnivorous fish.
2. Candidates were asked questions about various parts of the system. For example, how the nitrogen cycle makes nitrogen in urine and feces available to plants, the advantages of growing legumes, and the benefits of stocking the pond with algae-feeding fish rather than carnivorous fish.
The document describes a system designed to meet the basic needs of a family of four living in the tropics. The system uses natural processes to cycle nutrients between different components. Urine and feces from humans and livestock are used to fertilize crop plants through the nitrogen cycle. A fermenter containing bacteria breaks down liquid waste, while solid waste is used directly as fertilizer. Algae in a shallow pond produce carbon dioxide and oxygen, and are eaten by fish which provide a source of protein. This sustainable system recycles resources to grow crops and raise animals.
Deforestation, especially in tropical rainforests over the past 60 years, has contributed to both local decreases in biodiversity and global climate effects. Deforestation and the burning of fossil fuels have increased carbon dioxide levels in the atmosphere and global temperatures. New ideas to address global warming include planting trees on farms to offset industry emissions by acting as carbon sinks, and reducing plowing which allows soil to store more carbon.
This document discusses exam responses on topics related to carbon and nitrogen cycling. It provides feedback on common mistakes and omissions in student answers. For example, many students stated carbon is converted to oxygen during photosynthesis rather than being used to produce organic molecules. The document also notes better responses incorporated appropriate scientific terminology and integrated knowledge from the passage with their own biological understanding.
1. Most candidates understood how species conservation could result from selective logging but had difficulty clearly expressing these ideas. Some incorrectly imagined minerals redistributing over long distances from unlogged to logged areas. Most recognized the importance of sufficient time for tree regrowth.
2. Many candidates confused fertilizers and pesticides. Most explained ladybird consumption of greenflies accumulating insecticide but some incorrectly suggested insecticide increasing from greenfly reproduction. Patterns of population changes were often described poorly.
3. Candidates correctly identified interspecific competition but had difficulty calculating growth rate differences between spruce and heather in a control experiment.
Large-scale deforestation leads to environmental problems like soil erosion and decreased biodiversity. Sustainable logging of tropical rainforest helps conserve the ecosystem by only removing mature trees from sectors in sequence, allowing regeneration. Integrated pest management uses both chemical and biological controls, along with other practices, to manage pests in a balanced way while reducing chemical use. Enhancing environmental conditions in greenhouses, like carbon dioxide levels and temperature, can increase crop yields. However, overuse of fertilizers can pollute water sources with nitrates.
This document contains summaries of exam responses on topics related to ecology and succession:
1) Many candidates incorrectly described industrial effluent or slurry spillage instead of the provided explanation of weathered rock for shoreline deposits. Few could apply knowledge of succession to explain climax communities.
2) Most calculated diversity indices correctly but responses varied in interpreting the results. Better responses recognized adaptations allowing Fucus spiralis to outcompete others in its habitat.
3) Some wrote too much about succession where not required, failing to distinguish key points about changes in species numbers and individuals. Most described pioneer species roles but some unnecessary detailed climax communities.
4) Many misinterpreted the provided graph and did
The document describes a system designed to meet the basic needs of a family of four living in the tropics. The system uses natural processes to cycle nutrients between different components. Urine and feces from humans and livestock are used to fertilize crop plants through the nitrogen cycle. A fermenter containing bacteria breaks down liquid waste, while solid waste is used directly as fertilizer. Algae in a shallow pond produce carbon dioxide and oxygen, and are eaten by fish which provide a source of protein. This sustainable system recycles resources to grow crops and raise animals.
Deforestation, especially in tropical rainforests over the past 60 years, has contributed to both local decreases in biodiversity and global climate effects. Deforestation and the burning of fossil fuels have increased carbon dioxide levels in the atmosphere and global temperatures. New ideas to address global warming include planting trees on farms to offset industry emissions by acting as carbon sinks, and reducing plowing which allows soil to store more carbon.
This document discusses exam responses on topics related to carbon and nitrogen cycling. It provides feedback on common mistakes and omissions in student answers. For example, many students stated carbon is converted to oxygen during photosynthesis rather than being used to produce organic molecules. The document also notes better responses incorporated appropriate scientific terminology and integrated knowledge from the passage with their own biological understanding.
1. Most candidates understood how species conservation could result from selective logging but had difficulty clearly expressing these ideas. Some incorrectly imagined minerals redistributing over long distances from unlogged to logged areas. Most recognized the importance of sufficient time for tree regrowth.
2. Many candidates confused fertilizers and pesticides. Most explained ladybird consumption of greenflies accumulating insecticide but some incorrectly suggested insecticide increasing from greenfly reproduction. Patterns of population changes were often described poorly.
3. Candidates correctly identified interspecific competition but had difficulty calculating growth rate differences between spruce and heather in a control experiment.
Large-scale deforestation leads to environmental problems like soil erosion and decreased biodiversity. Sustainable logging of tropical rainforest helps conserve the ecosystem by only removing mature trees from sectors in sequence, allowing regeneration. Integrated pest management uses both chemical and biological controls, along with other practices, to manage pests in a balanced way while reducing chemical use. Enhancing environmental conditions in greenhouses, like carbon dioxide levels and temperature, can increase crop yields. However, overuse of fertilizers can pollute water sources with nitrates.
This document contains summaries of exam responses on topics related to ecology and succession:
1) Many candidates incorrectly described industrial effluent or slurry spillage instead of the provided explanation of weathered rock for shoreline deposits. Few could apply knowledge of succession to explain climax communities.
2) Most calculated diversity indices correctly but responses varied in interpreting the results. Better responses recognized adaptations allowing Fucus spiralis to outcompete others in its habitat.
3) Some wrote too much about succession where not required, failing to distinguish key points about changes in species numbers and individuals. Most described pioneer species roles but some unnecessary detailed climax communities.
4) Many misinterpreted the provided graph and did
1. Cycles
1. (a) Organic compounds of nitrogen / named example;
converted to ammonium compounds / ammonia;
by saprophytes / saprobionts / decomposers / equivalent;
to nitrites;
to nitrates;
by nitrifying bacteria / named bacteria;
uptake by roots; max 6
(b) (i) Nitrogen fixing bacteria / named e.g.;
in root nodules (of legumes);
convert nitrogen to ammonium / organic compounds (in legume);
released on decomposition;
and converted to nitrates; less need for fertiliser; max 4
(ii) Shorter food chain / less trophic levels;
will produce a greater yield of fish;
less energy lost between stages / more energy from producers;
(energy loss) in respiration / as heat;
fish prevent algal blooms / equivalent; max 3
[13]
2. (a) Release ammonia / ammonium / ammonification;
BY Decomposers / putrefying / saprotrophic / ammonifying bacteria;
ammonia → nitrite → nitrate / nitrification;
BY nitrifying bacteria / named bacteria; max. 3
(b) (Interspecific) competition;
for nitrates / nitrites / ammonia / ammonium compounds; 2
[5]
[Process is stand alone - bacteria only credited if in correct context.]
Hyde Clarendon Sixth Form College 1
2. 3. All essays are marked using the following scheme.
Scientific Content (maximum 16 marks)
Category Mark Descriptor
16
Most of the material of a high standard reflecting a
comprehensive understanding of the principles involved
Good 14 and a knowledge of factual detail fully in keeping with a
programme of A-level study. Some material, however,
may be a little superficial. Material is accurate and free
from fundamental errors but there may be minor errors
which detract from the overall accuracy.
12
10
A significant amount of the contents is of an appropriate depth
Average 8 reflecting the depth of treatment expected from a
programme of A-level study. Generally accurate if any
fundamental errors. Shows a sound understanding of
most of the principles involved.
6
4
Material presented is largely superficial and fails to reflect the
Poor 2
depth of treatment expected from a programme of A-
level study. If greater depth of knowledge is
demonstrated then there are many fundamental errors.
0
Breadth (maximum 3 marks)
Mark Descriptor
3 A balanced account making reference to most if not all areas that might
realistically be covered on an A-level course of study.
2 A number of aspects covered but a lack of balance. Some topics essential to
an understanding at this level not covered.
1 Unbalanced account with all or almost all material based on a single aspect.
0 Material entirely irrelevant
Hyde Clarendon Sixth Form College 2
3. Relevance (maximum 3 marks, one mark for each aspect)
Mark Descriptor
3 All material presented is clearly relevant to the title. Allowance should be
made for judicious use of introductory material.
2 Material generally selected in support of title but some of the main content of
the essay is of only marginal relevance.
1 Some attempt made to relate material to the title but considerable amounts
largely irrelevant.
0 Material entirely irrelevant or too limited in quantity to judge
-
Mark Descriptor
1 Spelling, punctuation and grammar of an acceptable standard.
1 Account presented in scientific language with correct use of technical
vocabulary.
1 Overall account logical and coherent.
[25]
4. (a) Mark for principle of placing quadrats at random;
marks for detail -
(method of) marking area out with grid/using tapes;
acceptable method of generating random numbers; e.g.
table/calculator; 3
(b) Any one correct change;
reason for diversity level;
explanation of how heather affects diversity; 3
(c) (i) Award two marks for 0.5 g m–2 yr–1;;
award one mark for answer without units
or 2.4 – 2.5 %; 2
(ii) Used for non photosynthesising/supporting organs;
eaten by grouse; 2
(iii) Younger plants have more shoots/provide more food;
Younger plants provide more cover;
Getting rid of old (unproductive) plants; max. 2
Hyde Clarendon Sixth Form College 3
4. (d) (i) proteins/nucleic acids/amino acids/ATP/nucleotides;
(ii) ammonium/nitrate/nitrite;
+ – –
NH 4 NO 3 NO 2 [Formula must correspond if given] 1
(e) Organic material/proteins to ammonia/ammonium compounds; 1
by saprobiotic/putrefying bacteria;
ammonia to nitrite;
nitrite to nitrate;
by nitrifying bacteria/named bacteria; max. 4
(f) In older stands, greater proportion of/more nitrogen in plants;
more lost when burnt: 2
[20]
5. (a) One mark for each correct column 2
Animalia/animal
Annelida/annelid
Class
Order
Family;
Lumbricus
(L.) terrestris;
(b) (i) Enzymes are proteins;
large molecules so not reabsorbed;
are not used up in reactions (which they catalyse);
enzymes are not themselves digested; max. 2
(ii) Add starch to worm casts;
test for reducing sugars with Benedict’s / test for disappearance
of starch with iodine;
need for control with boiled worm casts / soil; 3
(c) Fungicide also killing earthworms;
earthworms break leaves down into smaller pieces;
making more surface for microbial action;
OR
soil fungi / fungal decomposers killed;
less decomposition of leaves; max 2
Hyde Clarendon Sixth Form College 4
5. (d) (i) Nitrogen as inorganic ions/nitrate/ammonia / nitrite; 1
(ii) Nitrogen in waste products of metabolism/urea/uric acid /ammonia; 1
(ignore references to egestion)
(e) (i) Any TWO from:
Protein/amino acid/nucleic acid/ATP / urea; 1
(ii) Decomposers/saprophytic/putrifying bacteria release ammonia;
ammonia → (nitrite) → nitrate;
(named) nitrifying bacteria / nitrification; 3
(f) (i) Reduces surface area minimising water loss; 1
(ii) Using food stores resulting in excretory nitrogen; 1
(g) Addition of nitrogen;
from excretion / decay / enzymes;
removal of carbon;
when lost as carbon dioxide / during respiration; max. 3
[20]
6. (a) Energy losses due to radiation / evaporation / transpiration /
in photosynthesis / energy of wrong wavelength / some of
energy is heat;
Extras: cancel 1
(b) 2920; 1
(b) (Ammonium) → nitrite;
Nitrite → nitrate;
OR
Ammonium → nitrate; (1 mark only)
If symbols: correct symbols
e.g. ammonium ( nitrate (NO3) = NO MARKS
By nitrifying bacteria / Nitrosomonas / Nitrobacter / nitrification;
By oxidation / using oxygen / aerobic; 3 max
[5]
7. Quality of language
The answer to this question requires continuous prose. Quality of language should be
considered in crediting points in the mark scheme. In order to gain credit, answers must be
expressed logically in clear scientific terms.
Hyde Clarendon Sixth Form College 5
6. (a) Any three from:
Loss of habitat / nest sites / shelter / niche; ignore ‘homes’
Loss of food;
Exposure of soil leads to erosion / leaching of ions;
Change in (micro)climate / levels of light / temperature / humidity;
Animals move away / higher death rate / extinction; 3 max
(b) Any three from:
Absorb carbon dioxide; (extra carbon-sources CANCEL)
In photosynthesis;
Carbon (dioxide) is used in forming permanent plant tissues /
biomass / plant structures;
Carbon is incorporated in organic molecules / named e.g.; 3 max
(c) (i) Any four from:
Less oxygen can enter the soil (from the air);
For saprobionts / soil microorganisms / bacteria / fungi /
decomposers / correctly named soil organisms;
For use in aerobic respiration;
Less breakdown of organic matter / humus / dead plants /
dead animals / other e.g.;
Less carbon dioxide released / formed; 4 max
(ii) Any five from:
Oxygen enters the soil / use of oxygen;
Nitrifying bacteria are aerobic;
Ammonia / ammonium ions → nitrite;
Nitrite → nitrate;
(Ammonia → nitrate = 1 mark)
(If formulae used, worth 1 mark only if correct)
Nitrate is absorbed / used by plants;
To make named organic-N – e.g. protein / amino acids / DNA /
ATP / NAD(P) / chlorophyll;
Increased yield / growth; 5 max
[15]
Hyde Clarendon Sixth Form College 6
7. 8. (a) ‘Slash’ / cutting down trees reduces photosynthesis;
Reduces removal of carbon dioxide from atmosphere;
‘Burn’ combustion releases carbon dioxide;
OR ‘Slash’ cutting down trees removes respiring organisms;
Reduces removal of carbon dioxide into atmosphere;
‘Burn’ / combustion releases carbon dioxide; max 2
Hyde Clarendon Sixth Form College 7
8. (b) (Before clearing) soil exists / already produced;
(After clearing) recolonisation by new plants / seeds;
(Brings about) change in environment / soil;
(Allows) succession;
(Leading to) climax (community); max 3
(c) 1 Ammonium compounds from proteins / amino acids urea / N-containing;
2 Converted into nitrite;
3 Into nitrate; [Reject: Incorrect sequence once]
4 By nitrifying bacteria / correctly named;
5 Nitrogen-fixing bacteria;
6 Fix nitrogen from atmosphere / air;
7 Nitrate taken up by plants;
8 Nitrogen needed for protein synthesis / plant growth; max 6
(d) Trees available as a sustainable resource;
Maintain habitats / niches / shelter;
Maintain diversity / avoid loss of species / protect endangered species.
Maintain stability (of ecosystem);
Maintain food chains / webs / supply of food;
Reduced loss of soil / erosion;
Reduced flooding;
Act as carbon sink / maintainO2and C02 balance reduce greenhouse effect
Reduce global warming;
Source of medicines;
[Ignore: eutrophication] max 4
[15]
9. (a) Diaphragm/intercostal muscles contract;
Increases volume of thorax/chest/lungs;
Negative/lower pressure in lungs; 3
[Ignore: references to internal and external intercostal muscles]
(b) (i) Allows stabilisation/becomes steady/adapts; 1
(ii) 41.7 (dm3/litres); 1
(iii) Tidal volume increases steadily then levels out;
Breathing rate changes little until highest exercise rate/180 reached
then increases; 2
Hyde Clarendon Sixth Form College 8
9. [Note: Consider giving credit to answers where a specific part of the
range is defined and described accurately]
[7]
Hyde Clarendon Sixth Form College 9
10. 10. (a) (i) CO2 combines with RuBP/with ribulose bisphosphate;
(Product) splits in two/production of two molecules of GP/use
of RubisCo; 2
(ii) Amount formed = amount broken down/used/reference to Equilibrium; 1
(b) Any three from:
No ATP made (in dark);
No reduced NADP / NADPH (in dark); [Note: NOT “NADH”]
GP not converted (in dark);
TP not formed (in dark); max 3
(c) (i) During day/light photosynthesis occurs;
(Photosynthesis) uses/takes in CO2;
[Accept: converse explanation during darkness] 2
(ii) Higher;
Less light/cooler/fewer leaves/CO2 formed from soil organisms/decay
in soil/respiration in soil; 2
(d) Wind mixes air (with surrounding air)/removes CO2/supplies CO2;
Introduces another variable/makes data unreliable/takes account of wind; 2
(e) Any three from:
Detritivores/worms/woodlice/other e.g./decomposers/microorganisms/
bacteria/fungi;
Digestion/hydrolysis (of organic matter/of leaves)/decay/decomposition/
rotting;
Respiration;
Releases CO2; max3
[15]
11. (a) (i) Any four from:
1 Several/> 1 traps in each of the two habitats;
2 Place traps at random;
3 Details of method of achieving random layout/random coordinates
generated e.g. tables/calculators; [Reject: “throwing”]
4 Named factor held constant – e.g. same size traps/same length of time/
same time of day;
5 Count number of insects of each kind/type/species/count number of
kinds/ types/species present;
6 Calculate index of diversity (for forest and for field);
d = N (N - 1)
e.g. Σn(m − 1) = 1 mk + key to symbols = 2 mks max 4
Hyde Clarendon Sixth Form College 10
11. [Note: Consider giving credit to answers where a specific part of the
range is defined and described accurately]
[7]
Hyde Clarendon Sixth Form College 9