Triangle to calculate Magnification Converting units Required Practical

Triangle to calculate Magnification Converting units Required Practical 1 – Microscopy Use a light microscope to observe, draw and label a selection of plant and animal cells. Define magnification Define resolution Label the picture below 1 cm = mm 1 mm = μm 1 μm = nm Complete the table Size of image mm Magnification 5 X 200 15 Actual size μm 25 X 400 10 Write a method for this practical Compare the electron and light microscope Explain the importance of using a mounted needle, cover slip and stain

Variables Independent: Required Practical 2 – Microbiology (GCSE Biology only) Investigate the effect of antiseptics or antibiotics on bacterial growth using agar plates and measuring zones of inhibition. How did you work aseptically? What is meant by the zone of inhibition? How do you calculate it? Dependent: Control: Method Calculate the zone of inhibition for each antiseptic Why do you not seal the lid of the petri dish? Why are the petri dishes stored upside down at 25◦C? Describe the difference between antibiotics, antiseptics and disinfectants. How could you improve the Precision: Accuracy: State and explain which antiseptic was the most effective.

Variables Independent: Expected Graph Required Practical 3 – Osmosis Investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue. Definition of Osmosis Dependent: Control: Results Method Initial mass (g) Final mass in (g) 1. 0 M sugar solution 0. 5 M sugar solution Distilled water 10 10 10 5 10 25 How could you improve the Precision: % Change in mass in Analysis and Conclusion Accuracy: Define the terms Hypotonic: Hypertonic: Isotonic:

Variables Independent: Required Practical 4 – Enzymes Investigate the effect of p. H on the rate of reaction of amylase enzyme. Describe what is happening in the graph What does amylase break down? Dependent: Control: How is the temperature controlled? Hypothesis Why do we use iodine? Explain these results Method p. H 3 Enzyme Key words: p. H 7 p. H 9 p. H 12 How could you improve the Precision: Accuracy:

Food tests Test for Fat: Test for Sugars: Required Practical 5 – Food tests Use qualitative reagents to test for a range of carbohydrates, lipids and proteins. Suggested foods to be tested Control Emulsion test: Biuret reagent Benedict’s reagent: Ethanol Iodine Biuret reagent: Water bath Iodine test: Protein: The student says she was investigating continuous variables. Is she correct? Give your reasons. Risk Test tubes Fat: Carbohydrates: Hazard What does a positive result look like? Test for Protein: Test for Starch: Risk Assessment A student uses Benedict’s solution to test different foods for sugar. Suggest an explanation for these results. Complete the table Reagent Food group tested for Colour change before if food group is adding to present food colourless starch Benedict’s solution . Purple Food tested Final colour of Benedict’s solution A blue B brick-red C green D yellow

Variables Independent: Required Practical 6 – Photosynthesis Investigate the effect of a factor on the rate of photosynthesis using an aquatic organism such as pondweed. What is the inverse square law? - Higher Label the diagram Dependent: Expected Graph Control: Hypothesis Method Calculate the mean and highlight any anomalies Distance between the lamp and the pondweed in cm Number of bubbles collected in minutes 1 2 3 5 35 33 37 10 30 31 31 15 28 27 29 20 22 23 25 20 18 17 30 16 11 11 35 7 8 7 . 29 Mean What can you say about the effect of the independent variable on the dependent variable?

Variables Independent: Required Practical 7 – Reaction time Risk Assessment and ethical considerations Plan and carry out an investigation into the effect of a factor on human reaction time. Dependent: Control: Other possible ways to investigate reaction times Hypothesis Method Calculate the mean and highlight any anomalies Independent variable Number on the ruler in cm 1 st attempt 2 nd attempt 3 rd attempt 4 th attempt 5 th attempt Mean Silence Music Talking After caffeine How could you improve the. Precision: Accuracy: What can you say about the effect of the independent variable on the dependent variable?

Required Practical 8 (GCSE Biology only) Variables Investigate the effect of light or gravity on the growth of newly germinated seedlings. Independent: Describe two ways you could extend your experiment to do further investigations. Label the diagram Dependent: Control: Figure 1 shows some cress seeds that were grown in a box with light entering on one side. Explain the scientific reason for figure 1. Hypothesis Results – Calculate the mean Environme nt Height of seedling in full sunlight in mm 1 2 3 Light 25 28 27 No light 11 12 9 Explain why you used more than one seedling in each case. Mean Figure 1 How could you improve the Precision: Accuracy: What can you say about the effect of the independent variable on the dependent. variable?

State the function of a quadrat Risk Assessment Required Practical 9 – Field Investigations Measure the population size of a common species in a habitat. Use sampling techniques to investigate the effect of a factor on the distribution of this species. Method Results Sample site Co-ordinates Frequency of organism 5, 3 22 2, 6 43 Mean no of species present Abiotic factor investigation Distance along transect line (m) Light intensity (lux) % of grass cover 5 1, 304 35 1, 537 40 7, 2 29 10 15 1, 389 35 1, 8 43 20 2, 224 60 25 2, 114 65 30 2, 423 65 35 2, 455 60 Your quadrat has an area of 0. 25 m 2 Calculate the mean number of species present per m 2 Explain the effect of the abiotic factor on the % of grass cover. Calculate the estimated population size. Suggest any improvements you could make to the investigation to reduce any uncertainty in your results.

Variables Independent: Required Practical 10 – Decay (GCSE Biology only) Investigate the effect of temperature on the rate of decay of fresh milk by measuring p. H change. Explain why the decay of milk lowers the p. H Why is lipase used in this experiment? Dependent: Control: How is the temperature controlled? Expected Graph Hypothesis Results Method Temperature of milk in °C Time taken for solution to turn yellow, in seconds 1 2 3 20 30 35 32 40 10 11 9 60 5 7 8 80 6 6 7 Mean Two ways you could improve your experiment. What can you say about the effect of the independent variable on the dependent variable? How could you improve the. Precision: Accuracy: