• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Investigating The Effect Of Light Intensity On Cress Seedlings.

Extracts from this document...

Introduction

Investigating The Effect Of Light Intensity On Cress Seedlings Aim - To investigate whether or not light intensity affects the growth of cress seedlings. Hypothesis - I predict, the higher the light intensity, the more the cress seedlings will grow. Theory - The theory of photosynthesis states that a plant needs 4 things to photosynthesise and make food (glucose) for itself; these are light, chlorophyll, carbon dioxide and water. In addition, 3 factors affect the rate of photosynthesis; they are light intensity, carbon dioxide and temperature (as I am testing light intensity, carbon dioxide and temperature will be ket as controls to ensure a fair test). If the light intensity is low, the rate of photosynthesis, and growth of the seedlings, will slow down as well. This is because the chlorophyll in the cress can only photosynthesise and grow as fast as the light energy is arriving. ...read more.

Middle

and the size of the holes. Apparatus - * 6 Petri Dishes * Cotton Wool * Black Card * Hole Puncher * Cress Seeds * Sellotape Method - 1. I will cut 6 circles of card the same area of the surface area of the petri dishes and punch holes into them to alter light intensity; the number of holes will be 1, 3, 5, 7, 9 and 11. 2. I will then stick these onto the petri dish lids. 3. After that, I will flatten out the wool to 1cm in thickness and cut out 6 5cmx5cm squares, dampen them, and then put them into the petri dishes. 4. Fourthly, I will put 6 seeds into each dish, evenly spread out, and put the lids, with the pieces of card on them, back on. 5. Then I will put them onto a windowsill. ...read more.

Conclusion

I observed there was only a 0.08cm difference in height between the cress seedlings averages in the petri dishes with 3 and 5 holes. This is because, a seed already has a food store, and if the shoot cannot find sunlight it uses the food store it already has, to grow in search of sunlight. The result for the petri dish with 3 holes was the only anomalous result, all the rest were correct because I successfully blocked out any extra sunlight other than the light coming through the holes. Evaluation - If I were to do the experiment again I would find a better way to vary light intensity and I would like to be able to somehow measure the light intensity and put it into a graph in relation to the growth of the seedlings, to see if there are any other patterns to be observed. After doing this experiment I would like to test the affect of limited carbon dioxide and varying temperature on cress seedlings. ...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

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Marked by a teacher

    An investigation into the effect of a germination inhibitor on the germination of seeds.

    3 star(s)

    - This should be done twice a day, as said above, once in the morning and then again in the early afternoon. The times that the seeds are given water and inhibitor solution should be clearly noted, and it would be wise to give each pot their doses at around

  2. How temperature affects the rate of photosynthesis.

    For example if a pondweed was denatured at high temperatures, not enough pondweed was available to restart the whole experiment for that particular temperature again. So a different elodea length from a different parent plant had to be used. This plant could have had less number of leaves for the same length (50mm)

  1. Investigation into Cress Seeds

    As my necessary data had been collected, I produced graphs for all cultivars showing the variation. In addition to the six graphs, I produced a bar graph showing the average height for each cultivar. ANALYSING EVIDENCE: After analysing and comparing my graphs, my results show the cultivar with the least variation is the Lipidium.

  2. An investigation into the effects of different concentrations of lead chloride on the growth ...

    Soil was not used as a test medium because of its inconsistent composition, and not being homogenous. The mineral and nutrient content in the soil may not be uniform which would prevent a fair test from being carried out, as some seeds would be in surroundings with higher nutrient content than others in lower nutrient content environments.

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