2013 B Q1 (b) i &ii The diagrams below show two cells. Marks (i) The cell is placed in a hypertonic solution. Describe the appearance of the cell after one hour. 1 (ii) Explain why the animal cell would stay the same size when it is placed in an isotonic solution. 2 Question Acceptable Answer Not acceptable Negates Mark 1 (b) i Vacuole/cytoplasm shrunken Membrane/cytoplasm pulled away from wall/cytoplasm concentrated Plasmolysed/flaccid single words eg shrunken Plasmolysis It/cell shrinks 1 ii no net water movement/ water/osmosis in and out Equal (water/salt) concentration inside and out/ no concentration gradient Nothing happens Water does not move in or out Solution moving Water/salt equal Any reference to cell wall 1 1
Question Acceptable Answer Not acceptable Mark 8 (c) Stage 2 Nuclear membrane disappears / breaks down or Spindle forms or Chromosomes / (pairs of) chromatids / they move to equator / middle of cell Stage 4 Chromatids / they separate or Chromatids / they are pulled apart or Spindle fibres shorten Chromosomes shorten and thicken Chromatids join together at centromere Chromosomes / chromatids Chromosomes separate 1 1 (d) So there is no loss of information / So they have the same information (as parent cell) / So they have a full set of information / genes / all genes passed on So they have all the characteristics of the species – negates So they function properly So they have correct information Same genetics To stop mutation (negates) 1
St Gr. 2012 Q9 The diagrams below show two stages of mitosis in cells. Draw one straight line from each diagram to its correct description. 2 (b) 1 Question Acceptable Answer Not acceptable Mark 9 (a) Additional lines negate. 1 mark each. 2
(b) (Daughter cells) have identical information as the parent cell / Ensures that no information is lost / changed Daughter have a full chromosome complement Daughter cells have all the correct information (information : : DNA : chromosomes) Have the same number of chromosomes 1 DNA and the production of proteins Int 2 2011 B Q7(c) Marks 2 Question Acceptable Answer 7 (c) order, bases, protein 3 = 2 2/1 = 1 mark Int 2 2013 B Q9(a) Marks
2 Question Acceptable Answer 9 (a) bases amino acids proteins all 3 = 2 marks 2/1 = 1 mark Proteins and Enzymes St Gr. 2012 Q17(a) & (c) (a) Biological washing powders contain enzymes. Explain how enzymes work to remove stains. Marks 2 (c) Biological washing powders contain different enzymes. Explain why this is necessary. 1 Question Acceptable Answer Not acceptable Mark 17 (a) Digest stains / breakdown stains Makes stains more soluble / so stains can be washed out react with stains 1 1
A Q18 A Increasing milk in dairy cattle B Industrial melanism in Peppered moths C Insulin production by bacteria D Insertion of DNA into a bacterium 1 Question Acceptable Answer 18 D Int 2 2011 B Q1(b) The diagram below represents a potato cell. (b) Name the enzyme involved in the synthesis of starch in potato cells. Question Acceptable Answer 1(b) (potato/starch) phosphorylase Int 2 2011 B Q4 Enzymes are biological catalysts. The diagram below shows part of an enzyme controlled reaction. Marks (a) Describe the features of an enzyme which allow it to combine with only one substrate. 2
(b) What happens to an enzyme when it is boiled? 1 (c) Name a factor, other than temperature, which affects enzyme activity. 1 (d) Complete the following word equation for the enzyme catalase. 1 Question Acceptable Answer Not acceptable Mark 4 (a) enzyme has an active site (must be clear active site on enzyme) enzyme/active site is complementary/matching shape/specific to substrate Same enzyme/active site Enzyme fits substrate (or vice versa) 1 1 (b) denatured/ changes shape/ reduced activity/ stops working destroyed 1 (c) pH OR concentration of enzyme/substrate [any correct eg Higher] concentration 1
St Gr. 2013 Q5 (a) ii & (b) Two gardeners compared their tomato crops. Both grew 10 plants of the same variety in a greenhouse. One gardener altered the environmental conditions in his greenhouse to increase the rate of photosynthesis. His plants yielded 720 tomatoes. The other gardener only produced 480 tomatoes. Marks (ii) Describe two changes to the environmental conditions in the greenhouse which could have increased the rate of photosynthesis. 1 2 1 (b) (ii) Name a tissue in the leaves of plants in which photosynthesis takes place. 1 Question Acceptable Answer Not acceptable Mark 5 (a) Increased carbon dioxide / temperature / water / moisture / humidity / light / fertiliser Any two (must include increase, or equivalent) 1 (b) ii Mesophyll / spongy mesophyll / palisade mesophyll / palisade / lower epidermis Guard cells / upper epidermis / spongy layer 1 Int 2 2011 The diagrams below show four experiments used in an investigation into the conditions needed for photosynthesis. Marks
Question Acceptable Answer 7 B Int 2 2012 C Q1B The diagram shows the green water plant Elodea used in an experiment to investigate photosynthesis. Marks Describe how the requirements for photosynthesis shown in the diagram are used in photolysis and carbon fixation to produce oxygen and starch. 5 Answer Max Mark P1 (energy) from lamp absorbed by Elodea/plant/chlorophyll/ chloroplast P2 energy used to water Max 3 P3 into H and O P4 energy used to produce ATP C1 CO2 in joins with H C2 using (energy from) ATP C3 to form glucose Max 3 C4 glucose molecules joined to produce starch (any conversion) C5 enzyme controlled 5 Int 2 2013 B Q5 (a)