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Plants are autotrophic organisms; they are capable of converting inorganic substances – carbon dioxide and water – into organic substances, that is, glucose. They then convert glucose into other organic substances. Herbivorous animals satisfy their need for organic substances by eating plants, while carnivores eat other animals for this purpose. Therefore, plants are producers in the food chains.
Phases of photosynthesis
The two phases of photosynthesis are the light-dependent phase and the light-independent phase.
In the light phase of photosynthesis, light energy
is captured and oxygen is released.
Organic sugar is produced from inorganic carbon dioxide in the dark phase.
Oxygen (O2)
Glucose (C6H12O6)
Carbon dioxide (CO2)
Light
Water (H2O)
Oxygen (O2)
The process of photosynthesis
During photosynthesis, plants produce organic material, glucose from inorganic material, carbon dioxide, using the energy of light. Photosynthesis takes place in chloroplasts. This process requires water, and oxygen is formed as a by-product.
Carbon dioxide (CO2)
Materials involved in photosynthesis
The necessary carbon dioxide enters the leaves of plants through stomata; water is transported by the xylem in vascular bundles. The sugar that is produced is then transported to the rest of the plant by the phloem in vascular bundles, and oxygen is diffused into the atmosphere through the stomata.
Do all plants photosynthesise?
Photosynthesis takes place in the green parts of plants. Some plants do not have chloroplasts, therefore they produce organic material in a heterotrophic way. Such plants include the parasitic plants (such as dodders), which obtain all or part of their organic and inorganic nutrients from other plants.
The European dodder is a parasite plant, which does not contain chlorophyll.
Light
Water (H2O)
The importance of photosynthesis
1. During photosynthesis, plants produce organic material from inorganic material, therefore they are producers in food chains.
2. Glucose is stored in plants as starch, which constitutes an important nutrient for humans.
3. During photosynthesis, plants capture carbon dioxide and
release oxygen into the atmosphere.
The Anatomy and Development of Plants
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The Anatomy and Development of Plants
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