• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4

# Investigate a factor which may affect the rate of photosynthesis of Canadian pondweed.

Extracts from this document...

Introduction

Biology Coursework - To investigate a factor which may affect the rate of photosynthesis of Canadian pondweed... Aim: I plan to investigate whether light intensity affects the rate of photosynthesis of a length of Canadian pondweed, or ELODEA. This plant is suitable because it naturally occurs in water, so placing it in water for a prolonged period of time would not disturb it. Light intensity is measured in arbitrary units, and is calculated by using the formula Intensity = distance(from lamp) -2 or Intensity = 1 ? distance (from lamp)2 As the distance from the lamp increases, so the intensity decreases - they are INVERSELY PROPORTIONAL. Photosynthesis is a chemical reaction in plants that converts carbon dioxide and water into glucose and oxygen via a substance called CHLOROPHYLL. This is a green-pigmented chemical that absorbs sunlight and uses the energy to split water, thereby giving off oxygen bubbles. ...read more.

Middle

I will place an inverted syringe, filled with water, on top of the funnel, and use this to measure the volume of gas collected. The apparatus will then be placed at different distances from the irradiator, and I will use each distance to calculate the intensity of the light reaching the set-up. I will leave the apparatus like this for enough time to collect a measurable amount of gas, but so I can fit in as many different experiments as possible - and every 2 minutes I will record the volume of gas collected. Diagram: Table of Results: Distance (cm) Intensity (1/d2) Bubble Count Amended Intensity (intensity x 100,000) 10 0.01 72 1000 20 0.0025 80 250 30 0.001111111 107 111.1111111 40 0.000625 55 62.5 50 0.0004 53 40 60 0.000277778 28 27.77777778 70 0.000204082 23 20.40816327 80 0.00015625 19 15.625 90 0.000123457 14 12.34567901 100 0.0001 7 10 Analysis: From my results I gather that my hypothesis was correct, although the results are not an accurate display of this fact. ...read more.

Conclusion

Instead I just counted the number of bubbles. This proved not so accurate, but a lot easier to do. My hypothesis was proved correct, as the curve shows that there is (sort of...) a positive correlation between light intensity and bubble count. Evaluation: The experiment was not a resounding success, but did merely what I set out to do - prove my hypothesis correct, if only slightly. In order that I could obtain more accurate results, I could have done many things, including: � found the correct equipment to measure the volume, and done so � used a light meter to gauge the light intensity � repeated each distance more times to obtain an accurate average � used an automated data-logging machine of some kind to count the bubbles, thereby eliminating the factor of human error � found the rate of the reaction by involving time in my calculations Overall, my experiment was not astoundingly impressive, but served my purpose very well. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related GCSE Green Plants as Organisms essays

1. ## An investigation into the effect of light intensity on the rate of photosynthesis of ...

5 star(s)

As the light intensity increases from 4 to 5, the number of reaction decreases from 49 to 58 (increases 9). Compared with the increasing between light intensity 1 and light intensity 3, I can see that the increasing is just about the same between light intensity 4 and light intensity 5.

2. ## Factors That Affect the Rate of Photosynthesis

3 star(s)

�As the distance is further away, the length of bubble decreased, therefore the larger the bubble, the quicker because the more bubbles being collected by photosynthesis, the longer the bubble will be. �The rate of photosynthesis has increased steadily because our results state clearly that all our results are pretty

1. ## The aim of my experiment was to determine whether or not the intensity of ...

Eventually, a level will be reached where an increase in light intensity will have no further effect on the rate of photosynthesis, as there will be another limiting factor, in this case probably temperature. Preliminary work Initially, to ascertain a suitable range of distances at which to record results for

2. ## How temperature affects the rate of photosynthesis.

After this temperature the graph begins to level off. This temperature of 42.7 oC is the optimum temperature where all the enzymes involved in photosynthesis are working at their maximum capacity. The rate of oxygen production at this point is 59 mm3/min . At the optimum temperature, temperature is no longer the limiting factor.

1. ## Investigate one factor which will affect the rate of photosynthesis

I base this prediction on my background knowledge as well as previous experiments I have performed. In the spring and summer plants grow at a quicker rate than in winter and autumn. I believe that this is because light and heat are in a more plentiful supply.

2. ## Aim: To investigate a factor that affects the rate of photosynthesis

The size of the plant is also important since this would affect the amount of surface area for gas exchange. The only solution to controlling this variable is by using the same plant throughout the experiment. Limiting Factors- Light, carbon dioxide, temperature, and chlorophyll are all limiting factors, meaning that

1. ## How does light intensity affect the rate of photosynthesis of Canadian Pondweed?

most likely warm up the water in the beaker fractionally and I will need to add cold water in this case to keep the temperature of the water the same. I can now start the experiment. I am going to switch the lamp on and time for 5 minutes and

2. ## Factors That Affect Photosynthesis.

When measuring the light intensity in terms of LUC, the greater the distance, the slower the greater the rate of photosynthesis. While the photosynthetic rate increased, the rate at which it increased was decreasing. The first of these can be explained by the fact that light intensity is inversely proportional to the distance squared.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to