Biology Extended Essay

Table of Contents

Abstract…………………………………………………………………………………...2

Introduction…....................................................................................................................3

Theoretical Aspects………………………………………………………………………4

Affects of light intensities on plant photosynthesis measured by the amount of oxygen produced…………………………………………………………………………………..5

Experimental Aspects……………………………………………………………………6

Factors that Affect the rate of photosynthesis……………………………………...........7

Investigating the Affect of Light on plant photosynthesis…………………………......8

Hypothesis………………………………………………………………………………8.1

Variables………..………………………………………………………………………8.2

Apparatus..……………………………………………………………………………..8.3

Methodology……………………………………………………………………………8.4

Results………………………………………………………….……………………….8.5

A graph to show the Relationship between light and the rate of photosynthesis….....9

 Analysis & Conclusion………………………………………………………....9.1

 Extension Hypothesis

 Variables

 Materials

 Methodology

 Analysis & Conclusion

Conclusion

Bibliography

Further Research

IB Biology Extended Essay (Photosynthesis)

Candalus

Log lux

Thylakoids, add self observations

Abstract

An abstract is an abbreviated summary of a research article, review, or any in-depth analysis of a particular subject or discipline, and is often used to help the reader quickly ascertain the paper s purpose. When used, an abstract always appears at the beginning of a manuscript, acting as the point-of-entry for any given scientific paper or patent application.

Introduction

The subject of my Extended Essay is the “Effects of light intensities on plant photosynthesis measured by the volume of oxygen produced”. It is contained within the IB syllabus in Topic 7 on Cells Respiration and Photosynthesis. I intend to observe the volume of oxygen emitted by Elodea pond weed proportional to the differences in light intensities. After reading up on plant photosynthesis and rate of reaction from sunlight, I came to the conclusion that my hypothesis may be supported, I expect that there will be a big difference between the volume of oxygen produced from the pondweed in direct sunlight between the hours of 12:10 and 13:10 than those in front of a light bulb or in a dark cup board. For the analysis of photosynthesis I intend to record the volume of gas produced during a given amount of time, in this case a week, by using accurate measuring device such as a upside down measuring cylinder measuring the number of centimeters squared of gas produced on a given day in a consecutive 7 day week.

Photosynthesis:

All green plants must make their own food, this is carried out in a process called photosynthesis. For photosynthesis to occur they need sunlight energy. This energy is absorbed by a green pigment called chlorophyll, which is mainly found in the leaves of trees but also in aquatic plants. This energy then combines with water molecules (from the soil) and carbon dioxide (from the air). Because of this a sugar called glucose is made and also oxygen. For my experiment I have chosen to use