Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Mark Scheme Q1. Indicative Content QWC * Level 1 0 1-2 An explanation including some of the following points: water through the xylem capillary action osmosis into cells in the leaf evaporation from leaves transpiration stream diffusion into the atmosphere through stomata glucose converted to sucrose dissolved in water through the phloem bidirectionalmineral salts dissolved in water through the xylem from root to tip No rewardable content Mark (6) a limited explanation of the transport of one molecule e.g. water moves from roots to leaves the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple explanation of the transport of two molecules including correct reference to at least one of the vessels phloem or xylem. the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed explanation of the transport of all three molecules with correct reference to movement through phloem and xylem the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q2. Indicative Content QWC * Level 1 0 1-2 Mark An explanation including some of the following points: water through the xylem capillary action osmosis into cells in the leaf evaporation from leaves transpiration stream diffusion into the atmosphere through stomata glucose converted to sucrose dissolved in water through the phloem bidirectionalmineral salts dissolved in water through the xylem from root to tip No rewardable content (6) a limited explanation of the transport of one molecule e.g. water moves from roots to leaves the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple explanation of the transport of two molecules including correct reference to at least one of the vessels phloem or xylem. the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed explanation of the transport of all three molecules with correct reference to movement through phloem and xylem the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q3. Question Number QWC Indicative Content Level 1 0 1-2 2 3-4 3 5-6 Mark An explanation linking some of the following points • enzymes are proteins • mutation in DNA will result in different mRNA stran • during transcription • mRNA leaves the nucleus through the nuclear pore • the attachment of mRNA at the ribosomes • involvement of tRNA and amino acids • at the ribosome • which is translation • amino acid chain/peptide sequence altered • different protein (6) formed/protein not folded correctly No rewardable material • an attempt is made to link the change in the base sequence to the generation of a different amino acid • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy • there is evidence that the mutation is linked to a change in the protein • there may be an attempt to explain transcription of the incorrect code and translation of this although this explanation is likey to be unclear and may have missing steps • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately • spelling, punctuation and grammar are used with some accuracy • the response is likely to indicate the type of mutation and link this to a change of codon/protein • the response will show good evidence of understanding that an incorrect mRNA molecule is formed and translation by tRNA will result in an incorrect amino acid being incorporated into the protein chain • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately • spelling, punctuation and grammar are used with few errors Q4. QWC Level 1 * 0 1-2 Indicative Content A comparison between mitosis and meiosis including Mitosis (genetically) identical cells produced two daughter cells one division diploid daughter cells identical set of chromosomes occurs in the formation of body cells for growth and repair (of body tissues)Meiosis (genetically) non-identical cells four daughter cells 2 divisions haploid daughter cells half the number of chromosomes occurs in the formation of gametes for sexual reproduction results in genetic variation No rewardable content Mark (6) a limited description including two points on either meiosis or mitosis there maybe confusion between the two but this does not negate the level the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description including one comparison of meiosis and mitosis or a detailed description of either mitosis or meiosis the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed comparison of both meiosis and mitosis – at least two correct comparisons made the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q5. QWC Level 1 * 0 1-2 Indicative Content A description including use of body cell nucleus removed from body / parent cell use of egg cell nucleus removed from egg cell/enucleated egg nucleus (from body cell) transferred to enucleated egg electric shock; to stimulate cell division mitosis formation of embryo; embryo implanted into surrogate No rewardable content Mark (6) Limited description of 2 of the stages involved in cloning and the sequence of events is confused the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of 3 or more of the stages involved in cloning but some of the steps may be missing or out of sequence the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of 5 or more of the stages involved in cloning but the sequence is largely in order and complete the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q6. QWC * Level 1 0 1-2 Indicative Content A comparison between mitosis and meiosis including Mitosis (genetically) identical cells produced two daughter cells one division diploid daughter cells identical set of chromosomes occurs in the formation of body cells for growth and repair (of body tissues)Meiosis (genetically) non-identical cells four daughter cells 2 divisions haploid daughter cells half the number of chromosomes occurs in the formation of gametes for sexual reproduction results in genetic variation No rewardable content Mark (6) a limited description including two points on either meiosis or mitosis there maybe confusion between the two but this does not negate the level the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description including one comparison of meiosis and mitosis or a detailed description of either mitosis or meiosis the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed comparison of both meiosis and mitosis – at least two correct comparisons made the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q7. Indicative Content QWC * Level 1 0 1-2 A description including some of the following points in a logical sequence Names of enzymes: carbohydrases named carbohydrase eg amylase proteases named protease eg pepsin lipases named lipaseGeneral points about enzyme action: breakdown of large / insoluble / named molecules into small / soluble / named molecules for absorption catalysts speeds up reactions active sites that bind to substrate idea of specificitySpecific points: carbohydrates/ starch are broken down into sugars / glucose proteins /named protein are broken down into amino acids fats / oils / lipids / named lipid are broken down into fatty acids /glycerol No rewardable content Mark (6) a limited description of enzyme action that includes at least three points the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of enzyme action that includes at least six points the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of at least nine points the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q8. Indicative Content QWC * Level 1 0 1-2 Mark A description including some of the following points in a logical sequence Points relating to DNA structural features: two strands double helix (contains) bases A, T, C, G adenine / A paired with thymine / T guanine / G paired with cytosine / C hydrogen / H bonds joining basesContributions from Scientists: X-ray (crystallography) being used to show helical structure to show diameter of molecule how base pairs are arranged was shown how strands are arranged was shown modelling (6) reference to using other people's ideas No rewardable content a limited description that includes either: at least three DNA features OR one contribution the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description that includes at least three features of DNA and at least one contribution OR two features of DNA and two contributions. the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of the structure of DNA that includes at least three features and two contributions. the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q9. Indicative Content * Level 1 0 1-2 A description including there will less blood flow (to the muscles) because less blood leaving the heart less oxygen (reaching muscle) less glucose (reaching muscle) reduced rate of aerobic respiration less energy released less carbon dioxide removed greater rate of anaerobic respiration glucose broken down without oxygen reduced muscle contraction build up of lactic acid (in muscle cells) causing cramp / fatigue No rewardable content Mark (6) a limited description of 2 effects of reduced cardiac output on muscle the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of 4 or more effects of reduced cardiac output on muscle, but some steps maybe missing or out of sequence the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of 6 or more effects of a reduced cardiac output on muscle, with the sequence largely in order and complete the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q10. Q13. Question Number QWC * Level 1 0 1-2 2 3-4 3 5-6 Indicative Mark Content An explanation to include of the following points in a logical order • Coleus loses water from its leaves faster • therefore water drawn up Coleus faster • by transpiration • through the xylem • from the roots • details of transpiration given • Coleus could have a greater leaf surface area • because bigger leaves • Coleus could have more stomata • Coleus could have bigger stomata • more water taken in by osmosis • due to higher concentration in cells • reference to better root structure (6) No rewardable content • the response recognises that there is a link between how much water is lost and the recovery rate of the plants • there is an attempt to suggest differences in the leaves of the two plants • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy • the response recognises that the Coleus plant loses water faster and that this draws water up the plant faster, hence the faster recovery rate • there is an attempt to describe transpiration and to suggest a reasonable difference in the size of the leaves of the two plants • there is some understanding of the reasoning behind each of the processes • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately • spelling, punctuation and grammar are used with some accuracy • the response gives a clear explanation of transpiration and links it to the recovery of the Coleus • more than one difference between the two plants is given, with the top responses discussing differences relating to stomata • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately • spelling, punctuation and grammar are used with few errors Q14. Q15. QWC Level 1 2 3 Question Indicative Mark Number Content * An explanation to include of the following points in a logical order • Coleus loses water from its leaves faster • therefore water drawn up Coleus faster • by transpiration • through the xylem • from the roots • details of transpiration given • Coleus could have a greater leaf surface area • because bigger leaves • Coleus could have more stomata • Coleus could have bigger stomata • more water taken in by osmosis • due to higher concentration in cells • reference (6) to better root structure 0 No rewardable content 1-2 • the response recognises that there is a link between how much water is lost and the recovery rate of the plants • there is an attempt to suggest differences in the leaves of the two plants • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy 3-4 • the response recognises that the Coleus plant loses water faster and that this draws water up the plant faster, hence the faster recovery rate • there is an attempt to describe transpiration and to suggest a reasonable difference in the size of the leaves of the two plants • there is some understanding of the reasoning behind each of the processes • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately • spelling, punctuation and grammar are used with some accuracy 5-6 • the response gives a clear explanation of transpiration and links it to the recovery of the Coleus • more than one difference between the two plants is given, with the top responses discussing differences relating to stomata • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately • spelling, punctuation and grammar are used with few errors Q16 QWC Level 1 * 0 1-2 Indicative Content A description including some of the following points in a logical sequence Points relating to DNA structural features: two strands double helix (contains) bases A, T, C, G adenine / A paired with thymine / T guanine / G paired with cytosine / C hydrogen / H bonds joining basesContributions from Scientists: X-ray (crystallography) being used to show helical structure to show diameter of molecule how base pairs are arranged was shown how strands are arranged was shown modelling reference to using other people's ideas No rewardable content Mark (6) a limited description that includes either: at least three DNA features OR one contribution the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description that includes at least three features of DNA and at least one contribution OR two features of DNA and two contributions. the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of the structure of DNA that includes at least three features and two contributions. the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q18 QWC Level 1 * 0 1-2 Indicative Content A description including some of the following points in a logical sequence Names of enzymes: carbohydrases named carbohydrase eg amylase proteases named protease eg pepsin lipases named lipaseGeneral points about enzyme action: breakdown of large / insoluble / named molecules into small / soluble / named molecules for absorption catalysts speeds up reactions active sites that bind to substrate idea of specificitySpecific points: carbohydrates/ starch are broken down into sugars / glucose proteins /named protein are broken down into amino acids fats / oils / lipids / named lipid are broken down into fatty acids /glycerol No rewardable content Mark (6) a limited description of enzyme action that includes at least three points the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of enzyme action that includes at least six points the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of at least nine points the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q19 QWC Level 1 * 0 1-2 Indicative Content A description including use of body cell nucleus removed from body / parent cell use of egg cell nucleus removed from egg cell/enucleated egg nucleus (from body cell) transferred to enucleated egg electric shock; to stimulate cell division mitosis formation of embryo; embryo implanted into surrogate No rewardable content Mark (6) Limited description of 2 of the stages involved in cloning and the sequence of events is confused the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of 3 or more of the stages involved in cloning but some of the steps may be missing or out of sequence the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of 5 or more of the stages involved in cloning but the sequence is largely in order and complete the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q20 Question number * QWC 1 2 3 Indicative content Mark (6) a description to include some of the following: • diploid nucleus is removed from the body cell of a pink iguana/the organism to be cloned • a donor egg is enucleated/its nucleus is removed • the diploid nucleus from the animal being cloned is inserted into the enucleated egg cell • division of the nucleus is stimulated by electric shock/chemicals • cell divides by mitosis • cell is put into surrogate iguana (which creates an egg) • cell divides further and differentiates to form an embryo • organism that hatches from egg is a pink iguana The above points could be made diagrammatically, but a written description is also required. 1 - • limited description of stages involved in cloning a pink 2 iguana • many of the stages will be missing or in incorrect order • the process described is only partially complete and, if applied, would not result in a cloned animal • communicates ideas using simple language and some scientific terminology. Spelling, punctuation and grammar are used with limited accuracy 3 - • a detailed description of some of the stages involved in 4 cloning a pink iguana • some of the stages will be missing or in incorrect order • the process described is mostly complete and, if applied, may result in a cloned animal • communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately. Spelling, punctuation and grammar are used with some accuracy 5 - • a detailed description of the stages involved in the cloning of 6 a pink iguana • most or all of the stages will be present and in the correct order • the process described is complete and, if applied, would result in a cloned animal • communicates ideas clearly and uses a range of scientific terminology appropriately. Spelling, punctuation and grammar are used with few errors Q21 * Level 1 0 1-2 Indicative Content A description including there will less blood flow (to the muscles) because less blood leaving the heart less oxygen (reaching muscle) less glucose (reaching muscle) reduced rate of aerobic respiration less energy released less carbon dioxide removed greater rate of anaerobic respiration glucose broken down without oxygen reduced muscle contraction build up of lactic acid (in muscle cells) causing cramp / fatigue No rewardable content Mark (6) a limited description of 2 effects of reduced cardiac output on muscle the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of 4 or more effects of reduced cardiac output on muscle, but some steps maybe missing or out of sequence the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of 6 or more effects of a reduced cardiac output on muscle, with the sequence largely in order and complete the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q23 * Level 1 0 1-2 Indicative Content A description including fertilisation of egg by sperm ref to fusion of nuclei forming diploid cell ref to zygote (zygote) divides by mitosis to form identical cells several mitotic divisions growth of foetus examples of how fetus grows eg in height, mass stem cells in embryo specialisation / differentiation of (stem) cells into different cell types examples of different cell types eg neurones, skin cells development of fetus No rewardable content Mark (6) a limited description including 2 or more comments about one process the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description including 2 or more comments on 2 processes the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description including 2 or more comments on all 3 processes the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q24 QW C * Leve l 1 0 2 3-4 3 5-6 1-2 Question Indicative Content Mark Number An explanation linking some of the following points • enzymes are proteins • mutation in DNA will result in different mRNA stran • during transcription • mRNA leaves the nucleus through the nuclear pore • the attachment of mRNA at the ribosomes • involvement of tRNA and amino acids • at the ribosome • which is translation • amino acid chain/peptide sequence altered • different protein formed/protein not folded correctly (6) No rewardable material • an attempt is made to link the change in the base sequence to the generation of a different amino acid • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy • there is evidence that the mutation is linked to a change in the protein • there may be an attempt to explain transcription of the incorrect code and translation of this although this explanation is likey to be unclear and may have missing steps • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately • spelling, punctuation and grammar are used with some accuracy • the response is likely to indicate the type of mutation and link this to a change of codon/protein • the response will show good evidence of understanding that an incorrect mRNA molecule is formed and translation by tRNA will result in an incorrect amino acid being incorporated into the protein chain • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately • spelling, punctuation and grammar are used with few errors Q25 Question number * QWC 1 2 3 Indicative content Mark an explanation to include some of the following: • volume (6) of oxygen consumed during exercise increases • because of increased aerobic respiration • an oxygen deficit is built up during exercise • as a result of anaerobic respiration • during exercise breathing rate increases • oxygen absorbed more quickly/more oxygen transported in the bloodstream • aerobic respiration increases until oxygen cannot reach cells any faster • anaerobic respiration starts/increases as well as aerobic respiration • lactic acid is produced • which may cause cramp • continue to breathe heavily after race until return to resting rate • EPOC is used to process lactic acid • in liver • EPOC = the oxygen deficit whilst exercising 1 • a limited explanation of the effect of exercise on oxygen - consumption • there is some attempt to explain the physiological 2 effects of exercise on oxygen consumption in terms of more oxygen is needed • communicates ideas using simple language and some scientific terminology. Spelling, punctuation and grammar are used with limited accuracy 3 • a clear but incomplete explanation of the main effects of - exercise on oxygen consumption • the response is likely to 4 explain the physiological effects in terms of increased oxygen/aerobic respiration and production of lactic acid, but fails to explain the change in oxygen consumption • communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately. Spelling, punctuation and grammar are used with some accuracy 5 • a clear explanation of the effect of exercise on oxygen - consumption, oxygen deficit and EPOC • the response explains 6 the physiological effects in terms of increased oxygen consumption, aerobic and anaerobic respiration and the removal of lactic acid • communicates ideas clearly and uses a range of scientific terminology appropriately. Spelling, punctuation and grammar are used with few errors Q26 QWC Level 1 * 0 1-2 Indicative Content An evaluation including some of the following points: Strengths thin membrane permeable membrane presence of amylase presence of (large) starch molecules digestion into glucose glucose diffuses out concentration gradient water represents the blood weaknesses membrane not one cell thick not a large surface area shorter length / not same size no villi /micro villi only carbohydrate digestion no other enzymes present no peristalsis no blood movement other factors e.g. pH No rewardable content Mark (6) a limited evaluation of the model including at least one strength OR weakness of the model the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple evaluation of the model showing evidence of at least one strength AND at least one weakness of the model OR a detailed evaluation of several strengths or several weaknesses of the model the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed evaluation, commenting on several of the strengths AND weaknesses of the model and its limitations the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors