Photosynthesis Lesson 2 6 mark question Describe what happens to glucose made in photosynthesis and the roles of products it is converted into

Question mark scheme (green pen time) Levels Expected responses Level 3 All information in answer is relevant, clear, organised and presented in a structured and coherent format. Specialist terms are used appropriately. Few, if any, errors in grammar, punctuation and spelling. (5-6 marks) Level 2 For the most part the information is relevant and presented in a structured and coherent format. Specialist terms are used for the most part appropriately. There are occasional errors in grammar, punctuation and spelling. (3-4 marks) Level 1 Answer may be simplistic. There may be limited use of specialist terms. Errors of grammar, punctuation and spelling prevent communication of the science. (1-2 marks) Level 0 Insufficient or irrelevant science. Answer not worthy of credit. (0 marks) transported as soluble sugars but is stored as insoluble starch. glucose and starch can be converted to other substances in plants to be used for energy, growth and storage products. (lower level) Glucose and starch converted to other substances in plants and their use: • glucose for energy (respiration) • cellulose for cell walls • proteins for growth and repair • starch, fats and oils for storage.

Lesson 3 - 6 mark question Explain how leaves and the individual cells within the leaf are adapted for photosynthesis

Question mark scheme (green pen time) Levels Expected responses Level 3 All information in answer is relevant, clear, organised and presented in a structured and coherent format. Specialist terms are used appropriately. Few, if any, errors in grammar, punctuation and spelling. (5-6 marks) Level 2 For the most part the information is relevant and presented in a structured and coherent format. Specialist terms are used for the most part appropriately. There are occasional errors in grammar, punctuation and spelling. (3-4 marks) Level 1 Answer may be simplistic. There may be limited use of specialist terms. Errors of grammar, punctuation and spelling prevent communication of the science. (1-2 marks) Level 0 Insufficient or irrelevant science. Answer not worthy of credit. (0 marks) • broad so large surface area • thin so short distance for gases to diffuse • contain chlorophyll and other pigments to absorb light from different parts of the spectrum • have a network of vascular bundles for support and transport • guard cells which open and close the stomata. Higher level answers will:- Explain how the cellular structure of a leaf is adapted for efficient photosynthesis: • epidermis is transparent • palisade layer at the top containing most of the chloroplasts • air spaces in the spongy mesophyll allow diffusion between stomata and photosynthesising cells • internal surface area to volume ratio very large.

Lesson 4 – 6 mark question

Light shining on beaker Levels Expected responses Level 3 A description of how the apparatus is used to measure the rate of photosynthesis at different light intensities is given. For full marks reference must be made to a control variable (5-6 marks) Level 2 A description of how the apparatus is set up and a description of how photosynthesis can be measured or a description of how light intensity is varied or a control variable (3-4 marks) Level 1 A partial description of how the apparatus is set up or a simple description of how photosynthesis can be measured or a control variable (1-2 marks) Level 0 Insufficient or irrelevant science. Answer not worthy of credit. (0 marks) Apparatus set up: Weed in water in beaker Light shining on beaker Method of varying light intensity – e.g. changing the distance of lamp from plant Method of controlling other variables Use same pond weed or same length of pond weed Temperature: water bath or heat screen CO2 – use same amount of sodium bicarbonate Leave sufficient time at each new light intensity before measurements are taken Method of measuring photosynthesis e.g. counting bubbles of gas released or collecting gas and measuring the volume in a syringe Measuring the rate of photosynthesis by counting bubbles for set period of time repetitions

Lesson 5 – 6 Mark Question

Lesson 6 – Increasing food production A farmer keeps his crop of tomatoes in a greenhouse. Describe and explain what happens to the amount of carbon dioxide at points Y and Z.

• At point Y more carbon dioxide is being released Levels Expected responses Level 3 All information in answer is relevant, clear, organised and presented in a structured and coherent format. Specialist terms are used appropriately. Few, if any, errors in grammar, punctuation and spelling. (5-6 marks) Level 2 For the most part the information is relevant and presented in a structured and coherent format. Specialist terms are used for the most part appropriately. There are occasional errors in grammar, punctuation and spelling. (3-4 marks) Level 1 Answer may be simplistic. There may be limited use of specialist terms. Errors of grammar, punctuation and spelling prevent communication of the science. (1-2 marks) Level 0 Insufficient or irrelevant science. Answer not worthy of credit. (0 marks) • At point Y more carbon dioxide is being released • At point Z the amount of carbon dioxide has decreased • There was a higher level of CO2 in the greenhouse between midnight and dawn because plants can’t photosynthesise when it’s dark. Between dawn and dusk the amount of CO2 slowly decreases because it is being used for photosynthesis Between midnight and dusk the plant cells will perform respiration It uses stores of glucose and oxygen from the air to release energy as well as CO2 and water This causes the amount of carbon dioxide to increase between midnight and dawn

Lesson 7 - Diffusion

Importance of diffusion: Levels Expected responses Level 3 There is a description of a process occurring in either animals or plants that is linked to a substance and a process occurring in the other type of organism that is correctly linked to a substance (5-6 marks) Level 2 At least one example of a substance is given and correctly linked to a process either in animals or plants (3-4 marks) Level 1 An example of a named substance or a process or there is an idea of why diffusion is important e.g. as definition(1-2 marks) Level 0 Insufficient or irrelevant science. Answer not worthy of credit. (0 marks) Importance of diffusion: To take in substances for use in cell processes Products from cell processes removed Processes and Substances: For gas exchange/respiration O2 in/CO2 out For gas exchange/photosynthesis CO2 in/O2 out Food molecules absorbed: glucose/amino acids etc Water absorbed into large intestine Water loss from leaves – transpiration Water absorption by roots Mineral ions absorbed by roots

Transpiration Describe how water is lost from a plant and explain how this loss can be increased.

Question mark scheme (green pen time) Levels Expected responses Level 3 All information in answer is relevant, clear, organised and presented in a structured and coherent format. Specialist terms are used appropriately. Few, if any, errors in grammar, punctuation and spelling. (5-6 marks) Level 2 For the most part the information is relevant and presented in a structured and coherent format. Specialist terms are used for the most part appropriately. There are occasional errors in grammar, punctuation and spelling. (3-4 marks) Level 1 Answer may be simplistic. There may be limited use of specialist terms. Errors of grammar, punctuation and spelling prevent communication of the science. (1-2 marks) Level 0 Insufficient or irrelevant science. Answer not worthy of credit. (0 marks) - transpiration as the evaporation and diffusion of water from inside leaves. transpiration causes water to be moved up xylem vessels. Occurs at the stomata transpiration provides plants with water for cooling, photosynthesis, support and movement of minerals. transpiration rate increased by (higher level answer will include explanations): • increase in light intensity –More stomata open to lose water from • increase in temperature – water molecule/particles have more kinetic energy • increase in air movement – Moving water away from plant increases diffusion gradient • decrease in humidity. – air less saturated in water/lower water concentration in air, greater diffusion of water away from plant