Additional Science - Biology 2 Marking Scheme. Foundation Tier. 1. (a) 34 [1]

Transcription

1 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 4 Additional Science - Biology 2 Marking Scheme Foundation Tier. (a) 34 [] (b) genetic composition of daughter cells is not identical to mother cell/ owtte [] Question total [2] 2. (a) same material concentration of solution/volume or quantity of powder or enzyme or water; ph/acidity/alkalinity quantity/thickness/area of stain [3] (Any 3) (b) (i) 35 o C [] (ii) most stain removed (not: ref. optimum /works best at this temperature) [] (iii) Reference to taking repeat readings [] Reference to need to test temperatures between 35 o C and 80 o C. [] Question total [7] 3. (a) (i) the peas are carrying out respiration and so are giving off heat [] (ii) decomposers/bacteria/fungi are present [] and are respiring/giving off heat [] (b) (i) to retain heat/ owtte [] (ii) to allow gases to diffuse/because oxygen is needed for respiration [] Question total [5]

2 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials (a) Two marks can be awarded for two correct and relevant points e.g. photosynthesis (is taking place) [] which removes / absorbs / uses CO 2 [] (not: ref. to respiration) The third mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g. so less acidity / more alkaline/owtte. [] (b) it uses / absorbs / takes most CO 2 /carries out most photosynthesis/takes in CO 2 fastest [] (not: more) (c) very large leaf [] (d) small leaf [] 5. (a) A. rib [] B. bronchus [] C. alveolus [] (b) (i) One mark can be awarded for a correct and relevant point e.g. oxygen diffuses from alveoli/ lung [] The second mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g. into blood so less is in air breathed out [] (allow: used for () respiration ()) (ii) One mark can be awarded for a correct and relevant point e.g. carbon dioxide diffuses from blood [] The second mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g. into alveoli/lung so more is in air breathed out [] (allow: CO 2 produced () in respiration ()) Question total [7] 6. (a) eaten/killed by rat / stoat [] Its food is eaten by possum / deer / rabbit [] (not: competition unqualified) (b) easier to remove all the predators / competitors could be kept out/avp [] (c) Conflict between man and animals for land Land used for crops so loss of habitat Removing other animals from island to make way for kakapo Shouldn t be allowed to die out as may be useful in the future Loss of biodiversity / AVP [] Question total [4]

3 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials (a) Three marks can be awarded for three correct and relevant points e.g. water passes out of the cells (not: ref. to solution or liquid) [] from high water potential to low or correct description e.g. from where it is in high concentration to where it is in low concentration/water passes down a concentration gradient [] through a selectively permeable membrane [] The fourth mark can only be awarded if the candidate coherently and correctly links the consequence to the points above e.g. this causes a loss of support/potato becomes less firm /flaccid/becomes soft so it bends [] (b) put it in water/weaker solution (allow: add water) [] 8. (a) A pancreas Question total [5] B large intestine [] (b) process which breaks down/changes; [] large insoluble molecules into small/soluble substances; [] so they can be absorbed. [] (c) carbohydrates/starch (to glucose*) by carbohydrases/amylase [] proteins (to amino acids*) by proteases [] fats (to fatty acids & glycerol*) by lipases [] Any of 3 products* from correct substrate [] Question total [8]

4 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials (a) (light) brown/yellow to dark/blue-black/black (not: blue) [] (b) Indicative content: The starch is digested/broken down by the carbohydrase /amylase to sugar/maltose/glucose. As iodine is dark blue/black in the presence of starch the amount of light passing through at the start is low. As the enzyme acts the colour changes from dark blue to lighter/blue/brown as the starch is broken down. The colour/ colour density changes shown on the graph therefore shows more light passing through as the colour changes. 5 6 marks The candidate constructs an articulate, integrated account correctly linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar. 3 4 marks The candidate constructs an account correctly linking some relevant points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar. 2 marks The candidate makes some relevant points, such as those in the indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar. 0 marks The candidate does not make any attempt or give a relevant answer worthy of credit. [6] (c) Straight horizontal line starting where line on graph starts and continuing to near end of axis [] (d) Add Benedict s [] Boil/heat STRONGLY/heat to any stated temperature 80 C/boiling water bath [] (not: warm/heat gently or just heat) Question total [0]

5 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials (a) The variety or number [] of different species in an area [] (not: the number of organisms) (b) (i) A (non-native) species introduced into a country/habitat. owtte e.g. an organism introduced into another country where it is not normally found. (human involvement implied) (not: a non-native species unqual.) [] (ii) Answers relating to a reduction in native plant species due to competition/ reduction in oxygen content in water could kill or eq. aquatic insects/fish/plants. [] (c) Reference to the biological control agents eating/destroying native/other plants/species/ref. introduce disease/ introduce weevil as it only eats floating pennywort. [] Reference to biological control agents becoming pests themselves/no native predator so it breeds and gets out of control or reduces biodiversity [] (not: ref. to could outcompete native species).

6 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 46. (a) A pancreas Additional Science - Biology 2 Marking Scheme Higher Tier B large intestine [] (b) process which breaks down/changes; [] large insoluble molecules into small/soluble substances; [] so they can be absorbed. [] (b) carbohydrates/starch (to glucose*) by carbohydrases/amylase [] proteins (to amino acids*) by proteases [] fats (to fatty acids & glycerol*) by lipases [] Any of 3 products* from correct substrate [] Question total [8] 2. (a) (light) brown/yellow to dark/blue-black/black (not: blue) [] (b) (c) Indicative content: The starch is digested/broken down by the carbohydrase /amylase to sugar/maltose/glucose. As iodine is dark blue/black in the presence of starch the amount of light passing through at the start is low. As the enzyme acts the colour changes from dark blue to lighter/blue/brown as the starch is broken down. The colour/ colour density changes shown on the graph therefore shows more light passing through as the colour changes. 5 6 marks The candidate constructs an articulate, integrated account correctly linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar. 3 4 marks The candidate constructs an account correctly linking some relevant points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar. 2 marks The candidate makes some relevant points, such as those in the indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar. 0 marks The candidate does not make any attempt or give a relevant answer worthy of credit. Straight horizontal line starting where line on graph starts and continuing to near end of axis [] (d) Add Benedict s [] Boil/heat STRONGLY/heat to any stated temperature 80 C/boiling water bath [] (not: warm/heat gently or just heat) [6] Question total [0]

7 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials (a) The variety or number [] of different species in an area [] (not: the number of organisms) (b) (i) A (non-native) species introduced into a country/habitat. owtte e.g. an organism introduced into another country where it is not normally found. (human involvement implied) (not: a non-native species unqual.) [] (ii) Answers relating to a reduction in native plant species due to competition/ reduction in oxygen content in water could kill or eq. aquatic insects/fish/plants. [] (c) Reference to the biological control agents eating/destroying native/other plants/species/ref. introduce disease/ introduce weevil as it only eats floating pennywort. [] Reference to biological control agents becoming pests themselves/no native predator so it breeds and gets out of control or reduces biodiversity [] (not: ref. to could out compete native species). 4. (a) Unspecialised/undifferentiated cells that can develop into other cells [] (b) (c) Stem cells have 'changed'/differentiated into tendon cells which have replaced the damaged tissue. [] (not: tendons) Reference to: concerns about use of human embryos in experimental work because embryos are destroyed after 4 days/ethical/religious concerns about using embryos that have the ability to develop into humans; [] can be used to cure disease by targeting areas specifically/limited side effects compared to drugs. [] Question total [4]

8 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials (a) Increase in light intensity gives an increase in starch production (or converse). [] (b) Starch is turned to sugar at night as photosynthesis is not taking place. [] (c) (i) (2) noon. [] (ii) Two marks can be awarded for two correct and relevant points e.g. oxygen is produced by photosynthesis [] from the graph most light/maximum light is at noon [] The third mark can only be awarded if the candidate coherently and correctly links the consequence to the point above e.g. therefore maximum rate of photosynthesis and oxygen production is at noon [] 6. (a) (i) carbon dioxide produced which [] exerted pressure/pushed it down (not: ref. to volume) [] (ii) more energy/heat is being released/produced [] by respiration [] (iii) microbes/bacteria would use glucose/respire [] (b) (ethanol) acts as a poison/kills yeast [] (not: stops yeast working)

9 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials Indicative content: The advert encouraged people to smoke by promising relief from some illnesses/conditions; however, the links between smoking and some illnesses are now recognised and scientifically understood e.g. tar and cancer, infections due to mucus accumulation as the cilia no longer function. It is also known that there is addiction due to nicotine. The beneficial claims in the advertisement are now known to be untrue e.g. relief of asthma/doesn t cure diseases and doesn t cause influenza. As a result of recent knowledge about such health issues, there has been a change in attitudes to smoking e.g. less smoking now/people trying to give up/ smoking socially unacceptable/less advertising now / less sponsorship. There is now more active discouragement and more regulation e.g. warnings on packets/restriction on under-age sales/smoking-free zones imposed by law/ ban in public places. 5 6 marks The candidate constructs an articulate, integrated account correctly linking relevant points, such as those in the indicative content, which shows sequential reasoning. The answer fully addresses the question with no irrelevant inclusions or significant omissions. The candidate uses appropriate scientific terminology and accurate spelling, punctuation and grammar. 3 4 marks The candidate constructs an account correctly linking some relevant points, such as those in the indicative content, showing some reasoning. The answer addresses the question with some omissions. The candidate uses mainly appropriate scientific terminology and some accurate spelling, punctuation and grammar. 2 marks The candidate makes some relevant points, such as those in the indicative content, showing limited reasoning. The answer addresses the question with significant omissions. The candidate uses limited scientific terminology and inaccuracies in spelling, punctuation and grammar. 0 marks The candidate does not make any attempt or give a relevant answer worthy of credit.

10 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials (a) Movement of water from where it/water is in high concentration to where it/water is in low concentration/or down a concentration gradient [] (allow: correct references to solutes) Through a selectively permeable membrane [] (b) One mark can be awarded for a correct and relevant point e.g. modern lenses allow oxygen to pass through/reach cornea so allows respiration to continue aerobically [] Mark points 2, 3 and 4 can only be awarded if the candidate coherently and correctly links the consequences e.g. therefore no build up/production of lactic acid occurs (not: anaerobic respiration) [] so no/little osmosis/less water entering cornea [] which means there is no pressure build up (not: ref. pain) [] (not: water can t get through glass) Answer only to refer to why modern lenses are suitable i.e. no reverse argument 9. (a) Does not account for clumping / may miss a species / some areas left unsampled or sampled more than once. (Any 2) [2] (b) (i) Record: the number of trout captured and marked in the first sample/ initially; (x) [] the total number of trout caught in the second sample/recaptured; (y) [] the number of trout recaptured/in the second sample which were marked. (z) [] Appropriate formula for calculating estimate of population e.g. x y [] z (ii) (I) Marking does not affect or make animals more conspicuous to predators / does not affect chances or probability of being caught [] (II) It assumes that immigration rate is same as/balanced by emigration rate [] Question total [8]

11 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 53 MARK SPECIFICATION GRID Additional Science - Biology 2 Specimen assessment FOUNDATION TIER B2- Cells and metabolism, digestion and respiration, biodiversity Assessment Objective Total Mark AO AO2 AO3 Target Totals for Paper HSW QWC Question Number Specification Reference. (a) (l) (m) (b) 2 2. (a) 3 (b) (i) (i) (ii) 7 (iii) 2 3. (a) (i) (ii) 2 4 (a)(b) (b) (i) 5 (ii) 4. (a) 2 (b) 3 (b)(c) (c) 6 (d) 5. (a) 3 (b) (i) 6 (a) (d) 7 (ii) 6. (a) 2 (b) 7 (d) (e) 4 (c) 7. (a) (d) (e) (b) 5 8. (a) (b) 5 (d) (e) 3 8 (c) 3 9. (a) (b) (b) (d) 0 (c) (d) 0. (a) 2 (b) (i) 7 (d) (e) (ii) 6 (c) Raw Totals:

12 GCSE in ADDITIONAL SCIENCE Specimen Assessment Materials 54 MARK SPECIFICATION GRID Additional Science - Biology 2 Specimen assessment HIGHER TIER B2- Cells and metabolism, digestion and respiration, biodiversity Question Number Target Totals for Paper Specification Reference Assessment Objective AO AO2 AO3 Total Mark HSW QWC. (a) (b) 5(d) (e) 3 8 (c) 3 2. (a) (b) 5(b) (d) 0 (c) (d) 3. (a) 2 (b) (i) 7(d) (e) (ii) 6 (c) 4. (a) (b) (o) 4 (c) 5. (a) (i) (b) 3 (b) (c) (d), (d) (c) (i) 6 (ii) 2 6. (a) (i) (ii) 4(d), (h) (iii) 6 (b) 7. 6(f), (g) (a) 2 2(b) (e), 4(c) (d) (b) (a) 2 (b) (i) 7(c) 3 8 (ii) Raw Totals: