Compare the electron and light microscope Triangle to calculate Magnification Required Practical 1 – Microscopy Use a light microscope to observe, draw and label a selection of plant and animal cells. Converting units 1cm = mm 1mm = μm 1 μm = nm Define magnification Define resolution Label the picture below Complete the table Size of image mm Magnification Actual size μm 5 X 200 15 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

What is meant by the zone of inhibition? How do you calculate it? Variables Independent: Dependent: Control: 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. What is meant by the zone of inhibition? How do you calculate it? How did you work aseptically? Why do you not seal the lid of the petri dish? Method Calculate the zone of inhibition for each antiseptic 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.

Required Practical 3 – Osmosis Analysis and Conclusion Variables Independent: Dependent: Control: Required Practical 3 – Osmosis Investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue. Expected Graph Definition of Osmosis Method Results   1.0 M sugar solution 0.5 M sugar solution Distilled water Initial mass (g) 10   10 Final mass in (g)  5  25 % Change in mass in How could you improve the Precision: Accuracy: Analysis and Conclusion Define the terms Hypotonic: Hypertonic: Isotonic:

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

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

What is the inverse square law? - Higher Required Practical 6 – Photosynthesis Investigate the effect of a factor on the rate of photosynthesis using an aquatic organism such as pondweed. Variables Independent: Dependent: Control: What is the inverse square law? - Higher Label the diagram Expected Graph 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 Mean 5   35 33 37     10 30  31  15 28 27 29 20 22 23 25 18 17 30 16 11 35 7 8 What can you say about the effect of the independent variable on the dependent variable? .

Number on the ruler in cm Required Practical 7 – Reaction time Plan and carry out an investigation into the effect of a factor on human reaction time. Variables Independent: Dependent: Control: Risk Assessment and ethical considerations Other possible ways to investigate reaction times Hypothesis Method Calculate the mean and highlight any anomalies Independent variable Number on the ruler in cm 1st attempt 2nd attempt 3rd attempt 4th attempt 5th 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? .

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

5,3 22 2,6 43 7,2 29 1,8 Abiotic factor investigation State the function of a quadrat 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. Risk Assessment Method Results Sample site Co-ordinates Frequency of organism Mean no of species present 5,3 22 2,6 43 7,2 29 1,8 Abiotic factor investigation Distance along transect line (m) Light intensity (lux) % of grass cover 5 1,304 35 10 1,537 40 15 1,389 20 2,224 60 25 2,114 65 30 2,423 2,455 Your quadrat has an area of 0.25 m2 Calculate the mean number of species present per m2 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.

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