Primary productivity Lab Report Example | Topics and Well Written Essays - 500 words

Primary productivity - Lab Report Example time by calculating the amount of oxygen produced which is directly proportional the amount of carbon bound to organic compounds such as carbohydrates in photosynthesis. In this experiment the light and dark bottle method was used. A set of 24 clean bottles each with a capacity 300ml were prepared. Twelve of the bottles were covered with aluminum foil and a black tape while the other twelve were not covered. All the 24 bottles were then filled with algae water. All the bottles were then exposed to light for a period of 1 hour. Dissolved oxygen probes were prepared and allowed to stay in water for 5 minutes as the probe warmed up and the initial dissolved oxygen concentration recorded. Data in each bottle was collected by gently stirring the probe in the water sample until the readings were relatively stable for about 30 seconds and the values recorded. The values for the light and the dark bottles were recorded and the means calculated. The respiration rate, gross productivity and net productivity were then calculated. The means were compared using student’s t-test and considered significant at P The data obtained for the dissolved oxygen concentrations in the light and dark bottles were subjected to paired student’s t- test. The results obtained indicated that there was a significant (P The algae in the bottles exposed to light predominantly carry out photosynthesis as they trap light energy which is converted into chemical energy in the form of sugars. Photosynthesis leads to the production of O2 and thus explains the increased concentrations of the dissolved oxygen. In the dark bottle only respiration occurs since algae are C3 plants. Since there was no sunlight the plants did not manufacture more sugars but rather there was breakdown of the sugars to provide energy for cellular activities with the production of carbon