Page 1 - 2.Lesson notes-Autotrophic nutrition (I)- Essential conditions for photosynthesis.
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SAI International School

                                               Subject- Biology, Class-VII
                                                Topic-Nutrition in plants
                                           Subtopic- Autotrophic nutrition-1
                                                       Lesson Notes
               AUTOTROPHIC MODE OF NUTRITION-

               ●  The mode of nutrition in which organisms synthesise their own food using simple inorganic
                   materials such as carbon dioxide, water, and minerals by the process of photosynthesis.
               ●  Autotrophs- The organisms that can produce their own food. Ex- Green plants, and certain
                   bacteria.

               PHOTOSYNTHESIS-

               ●  The process by which green plants prepare their own food and produce glucose by utilising
                   carbon dioxide, water in the presence of sunlight and chlorophyll is called photosynthesis.
               ●  Equation of photosynthesis-










               ESSENTIAL CONDITIONS REQUIRED FOR PHOTOSYNTHESIS-

               1.  Chlorophyll-
                       ●  Green plants contain a green pigment called chlorophyll which is present in special
                          structures called chloroplast.
                       ●  Function- traps the solar energy which is then used as chemical energy in
                          photosynthesis.
                       ●  Leaves are not always green in plants. There are few pigments such as carotenoids
                          and phycobilins present in the plant body which impart different colour to the leaves

                          and can cover up for chlorophyll. Ex- Croton plant
               2.  Sunlight-
                       ●  Sunlight is trapped by chlorophyll and converted into chemical energy.
                       ●  It provides the energy needed by plants to convert carbon dioxide and water into
                          food.
                       ●  Without sunlight, plants cannot make their own food.
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