Limiting Factors

What is a limiting factor? Work in pairs to: discuss what is meant by a limiting factor come up with a definition

Identify the factors that affect the rate at which a plant can carry out photosynthesis. Match each factor with one of the graphs below. Explain why.

These are the three important graphs for rate of photosynthesis Annotate your graphs to explain how each factor affects the rate of photosynthesis You may want to include arrows to explain each section of the graph and what the limiting factors are.

Page 116 figure 10.10 – work in pairs to explain each curve on the graph. summary

Using your knowledge of limiting factors, revise or write a new definition for a limiting factor

Glasshouses Use your knowledge of photosynthesis and limiting factors to design a glasshouse. Ideal glasshouses britainslargestglasshouse http://www.bbc.co.uk/learningzone/clips/how-commercial-growers-improve-crop-yield/12902.html

Is the rate of photosynthesis affected by the light intensity? Plan an investigation (use DICOR) Dependent variable – what exactly are you going to measure and how (2 marks) Independent variable - what you are going to change and how Control variables – what other variables might affect the dependent variable and how will you make sure they stay the same (2 marks) Organism – if using living organisms think about controlling the species, age, sex, mass etc. (2 marks) Repeats – plan to repeat 5 times and calculate the mean

Homework Design an experiment to investigate if the rate of photosynthesis is affected by the light intensity. Use the guidelines on the top of page 117 (pink box). You will carry out the practical work next lesson so COMPLETE HOMEWORK BEFORE NEXT LESSON.