PHOTOSYNTHESIS

            Photosynthesis is the process by which green plants, algae and some bacteria use sunlight, carbon dioxide and water to prepare their food. This is a biogeochemical processes. It takes place in the chloroplast. The chlorophyll pigments present in chloroplast traps light energy and converts it into carbohydrate(glucose then into starch). During the process water molecules splits by light energy , hydrogen is used for the reduction of carbon dioxide into glucose(sugar carbohydrate) with release of oxygen as a by product.  The carbon dioxide enters the leaf through small openings called as stomata. Each stomata is guarded by two guard cells.

Questions-:

1.What is the first step in photosynthesis ?

             a)  formation of glucose

             b)  formation of ATP

              c)   absorption of light by chlorophyll pigment

              d)   release of oxygen

2. Factors that influence the photosynthesis ----------------.

3.During photosynthesis oxygen releases comes from which compound .

4.Carnivores are also dependent on green plants even though they eat flesh.  Justify the statement.

5.During photosynthesis

            a)  light energy is converted into heat energy.

            b)  light energy is converted into chemical energy .

            c)  chemical energy is converted into heat energy .

            d)  heat energy is converted into light energy .

                               Answer Key

Q1.  Full credit - option(c) Absorption of light by chlorophyll

     No credit – any other option

Q2.  Full credit -  light, chlorophyll, water & carbon dioxide

      Half credit- for any two correct answer

Q3.  Full credit -  Water

      No credit - for any other answer

Q4.  Full credit -  animals depend on plants for their food ,because they

                         Have no chlorophyll

      Partial credit –if required

Q5.   Full credit - 

         Option (b) Light energy is converted into chemical energy.  

       No credit -  for any other option