2 Elodea And Photosynthesis Lab
#2 Elodea and Photosynthesis by __________________
Name:_____________________
Class:_____________________
Teacher:_____________________
Date:_____________________
Elodea and Photosynthesis
Introduction:
Photosynthetic organisms (cyanobacteria) first evolved about 3.5 billion years ago and are the oldest know fossils on Earth. Cyanobacteria live in water, can manufacture their own food, and are one of the most important groups of bacteria on Earth. The Cyanobacteria have been important in shaping the course of evolution and ecological change throughout Earth’s history. Cyanobacteria took in atmospheric carbon dioxide, water and sunlight and converted it into sugar (glucose) and released the waste product oxygen.
Photosynthesis reduced the amount of carbon dioxide in the atmosphere, as oxygen was continually being released. For roughly a billion years, oxygen released by cyanobacteria did not build up in the atmosphere. It was used up by two sources: oceans and rocks. Oxygen dissolved in the oceans and oxidized (rusted) the exposed iron and other minerals, as seen in banded rock formations around the world. Approximately two billion years ago, the reservoirs of oxidizable rock became saturated and thus allowing the buildup of free oxygen in the air.
As oxygen moved into the early atmosphere, ultraviolet radiation from the sun split the oxygen molecules (O2), which then recombined, producing the Earth’s ozone layer (O3). This, in turn, reduced the amount of incoming ultraviolet radiation striking the Earth. The impact for life on Earth was enormous. With reduced amounts of ultraviolet radiation, organisms moved to shallow water and, ultimately, onto the land.
Materials:
Elodea stem (up to 10 cm – 4 inches). Store Elodea in oxygenated water, use as soon as possible after purchase.
Distilled water
Baking soda
Beaker
Lamp (60 – 100 watt)
Metric ruler
Large test tube
Single-edged razor blade
Timer or clock
Procedure:
1.
Name:_____________________
Class:_____________________
Teacher:_____________________
Date:_____________________
Elodea and Photosynthesis
Introduction:
Photosynthetic organisms (cyanobacteria) first evolved about 3.5 billion years ago and are the oldest know fossils on Earth. Cyanobacteria live in water, can manufacture their own food, and are one of the most important groups of bacteria on Earth. The Cyanobacteria have been important in shaping the course of evolution and ecological change throughout Earth’s history. Cyanobacteria took in atmospheric carbon dioxide, water and sunlight and converted it into sugar (glucose) and released the waste product oxygen.
Photosynthesis reduced the amount of carbon dioxide in the atmosphere, as oxygen was continually being released. For roughly a billion years, oxygen released by cyanobacteria did not build up in the atmosphere. It was used up by two sources: oceans and rocks. Oxygen dissolved in the oceans and oxidized (rusted) the exposed iron and other minerals, as seen in banded rock formations around the world. Approximately two billion years ago, the reservoirs of oxidizable rock became saturated and thus allowing the buildup of free oxygen in the air.
As oxygen moved into the early atmosphere, ultraviolet radiation from the sun split the oxygen molecules (O2), which then recombined, producing the Earth’s ozone layer (O3). This, in turn, reduced the amount of incoming ultraviolet radiation striking the Earth. The impact for life on Earth was enormous. With reduced amounts of ultraviolet radiation, organisms moved to shallow water and, ultimately, onto the land.
Materials:
Elodea stem (up to 10 cm – 4 inches). Store Elodea in oxygenated water, use as soon as possible after purchase.
Distilled water
Baking soda
Beaker
Lamp (60 – 100 watt)
Metric ruler
Large test tube
Single-edged razor blade
Timer or clock
Procedure:
1.