APPENDIX- 1 LESSON TRANSCRIPTS FOR WEB SITE LEARNING

Transcription

1 APPENDIX- 1 LESSON TRANSCRIPTS FOR WEB SITE LEARNING LESSON - 1 PHOTOSYNTHESIS The objectives of the lesson: 1. The pupil acquires the knowledge of photosynthesis. 2. The pupil understands the significance of photosynthesis. 3. The pupil analyses photosynthesis as the important biological process. 4. The pupil organizes, evaluates and makes inferences on the importance of photosynthesis. Anticipatory set Or Introduction In the earlier class itself you have learnt about Photosynthesis. Here we can learn about the significance of photosynthesis and analyse why photosynthesis has considered as the significant biological process required for human existence. Here the lesson is prepared in different phases: Input Or Procedure (1). The teacher presents the lesson in small steps. (2). The teacher guides the students to learn the lesson With divergent questions. (3). The teacher explains the questions through guided Practice. (4). Students learn the lessons through thought - Provoking questions without the help of the teacher.

2 Modelling Autotrophic plants prepare their own food material through the process called Photosynthesis. Photosynthesis is the process of synthesis of carbohydrates from carbondioxide and water in the presence of sunlight and chlorophyll. It is the most important synthetic process on earth. Here the solar energy is fixed in the form of chemical energy ie; the plants have the capacity of capturing light energy from the sun and converting it into chemical energy. Here the kinetic energy of sunlight is transformed in to chemical energy and stored in the carbohydrate molecules. This chemical energy is used for the growth and development of all forms of life in the universe. Approximately 90% of the world s photosynthesis is carried out by marine algae and fresh water algae and all animals depend on plants and their source of energy. Photosynthesis is considered as the natural physiobiological process of the world on which the existence of life in earth depends. So photosynthesis is the single most important biological process required for human existence. 1. Photosynthesis is the process of synthesis of. (Carbohydrate, Fat) 2. During photosynthesis energy is converted

3 Checking for understanding Into energy. (Light energy-chemical energy, Sound energy- Chemical energy) 3. 90% of photosynthesis is carried out by and. (Marine algae & Fresh water algae, Animals & Zooplankton) 4. The natural physio-biological process of the world is. (Photosynthesis, Respiration) Guided practice 1. Photosynthesis is process of synthesis of carbohydrate from Co 2 and water in the presence of sunlight and chlorophyll. 2. During photosynthesis light energy is converted into chemical energy. Here the light energy from the sun is taken not the Sound energy % of the photosynthesis is carried out by marine and fresh water algae. 4. The natural physio-biological process of the world is Photosynthesis.

4 Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. Independent practice And Closure of the Lesson 1. Why photosynthesis is considered as a significant process? 2. What is Photosynthesis? 3. During photosynthesis which energy is converted into chemical energy? 4. Which is the most important biological process required for human existence?

5 CORRECT ANSWER FOR LESSON 1 1. The photosynthesis is the most important synthetic process on earth. Here the solar energy is fixed in the form of chemical energy and stored in the carbohydrate molecule. This chemical energy is used for the growth and development of all forms of life in the universe. 2. Photosynthesis is the process of synthesis of carbohydrate from carbon dioxide and water in the presence of sunlight and chlorophyll. 3. During photosynthesis light energy is converted into chemical energy. 4. Photosynthesis is the most important biological process required for human existence.

6 LESSON - 2 CHLOROPLAST THE SITE FOR PHOTOSYNTHESIS The objectives of the lesson: 1. The pupil understands the importance of chloroplast in photosynthesis. 2. The pupil identifies the structure of leaf and its importance. 3. The pupil analyses the importance of photosynthetic apparatus. 4. The pupil differentiates the different shapes of chloroplast. 5. The pupil syntheses the knowledge that size and shape of chloroplast varies from species to species. Anticipatory set or Introduction The students understand the structure of a leaf and the arrangement of Chloroplast with the help of a diagram. The students will be able to Understand the importance of chloroplast in the process of Photosynthesis. The students learn the various size and shape of chloroplast with the help of diagrams. Teacher presents the lesson in different steps: Input or Procedure (1). Teacher explains the content in series of small steps. (2). Teacher checks the understanding of students with the help of multiple choice questions. (3). Teacher explains the content once again through guided practice. (4). Teacher makes a closure of lesson through independent practice.

7 Photosynthesis is the process of synthesis of carbohydrate from Co 2 and water in the presence of sunlight and chlorophyll. 6CO H 2 O C 6 H 12 O 6 + 6H 2 O + 6O 2 Here the photosynthesis takes place in the green parts of the plant body such as leaves, green stems and in green floral parts etc. In leaves the photosynthesis takes place in the mesophyll tissues. Structure of Leaf Modelling In the structure of a leaf the green tissues seen in between the upper and lower epidermis is the mesophyll tissue. The mesophyll is differentiated into palisade parenchyma and spongy parenchyma. Both these parenchyma cells contain the green plastid-

8 CHLOROPLAST. These chloroplasts are the characteristic structure of green plants. The chloroplasts are green due to the presence of green pigment chlorophyll. Here the chloroplasts are considered as the seats of photosynthesis, they synthesis starch by using CO 2 and sunlight. So chloroplast is considered as the photosynthetic apparatus. The chloroplasts are distributed homogeneously in the cytoplasm of plant cell. Their diameter is about 5 to 8 µ. The size of the chloroplast varies from species to species. In green algae, the chloroplast has various shapes, example., Ribbon shaped (Spirogyra) Star shaped (Zygnema)

9 Girdle shaped (Ulothrix) Disc shaped (Caulerpa)

10 Reticulate shaped (Oedogonium) Cup shaped (Chlamydomanas) 1. Photosynthesis takes place only in. (Green parts, Flowers, Roots)

11 Checking for understanding 2. The green plastids seen in the cytoplasm are called. (Chloroplast, Palisade tissue, Vacuoles ) 3. is considered as the photosynthetic apparatus. (Mesophyll tissue, Flowers, Chloroplast ) 4. The diameter of the chloroplast varies from. (5-10 µ, 5-8 µ, 5-6 µ) 5. The shape of chloroplast in chlamydomonas is. (Star shaped, Girdle shaped, Cup shaped). Guided practice 1. Photosynthesis takes place only in the green parts of the plant body. For photosynthesis sunlight and chlorophyll is essential. Chlorophyll is seen in the green parts of the plant body. 2. In the leaves photosynthesis takes place in the mesophyll tissues. These mesophyll cells contain the green plastid - chloroplast. 3. Chloroplast synthesis starch by using CO 2, Water and Sunlight. So chloroplast is considered as the photosynthetic apparatus. 4. The diameter of chloroplast varies from 5 to 8 µ. 5. The shape of chloroplast in chlamydomonas is cup shaped. Star shaped in Zygnema and girdle shaped in Ulothrix.

12 Independent practice And Closure of the Lesson Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. 1. Why chloroplast is considered as the photosynthetic apparatus? 2. Why photosynthesis takes place in the green parts of the plant body? 3. Why photosynthesis doesn t takes place in the roots of the plants?

13 CORRECT ANSWER FOR LESSON 2 1. Chloroplast are the characteristic structure of green plants they synthesize starch by using co 2, water and sunlight. So chloroplast is considered as the photosynthetic apparatus. 2. Only in the green parts of the plant body chloroplast are seen. Only in the presence of chloroplast photosynthesis takes place. So photosynthesis takes place only in the green parts of the plant body. 3. In roots chloroplast are absent so photosynthesis doesn t takes place.

14 LESSON - 3 STRUCTURE OF CHLOROPLAST The objectives of the lesson: 1. The pupil understands the structure of chloroplast. 2. The pupil explains the importance of chloroplast. 3. The pupil analyses the role of chloroplast in the process of photosynthesis. 4. The pupil syntheses the knowledge about the functions of chloroplast. Anticipatory set or Introduction The teacher presents the lesson structure of chloroplast with the help of a diagram. The students try to learn the lesson using the diagram. Teacher presents the lesson in different steps: Input or Procedure (1). The lesson is presented with the help of a diagram. (2). Small questions are given for checking understanding. (3). Answers for the questions in the previous step is given. (4). Independent practice is given with the closure of the Lesson. (5). Correct answers for the questions in the independent Practice is given.

15 Now we can see the structure of chloroplast. Structure of Chloroplast Modelling The chloroplast is surrounded by two unit membrane. Each membrane is lipo-proteinaceous in nature. The space in between two membranes is known as periplastidial space. The space inside the chloroplast is filled with a proteinaceous fluid called Stroma. The stroma contains DNA, Ribosome s and Enzymes for carbon assimilation. The enzymes found in stroma are capable of utilizing ATP and NADPH 2 to produce

16 carbohydrates. A number of membrane bound, sac like structure are embedded in the stroma. The structures are called the Thylakoids or Lamellae. The thylakoids are seen in groups. Each group is known as Granum. Each thylakoid in a granum is called the grana thylakoid. The thylakoid which interconnects the adjacent grana is called the stromathylakoid or fret or intergranal thylakoid. Each thylakoid is also a double membrane-bound structure. The green pigment molecules, chlorophyll are seen as units inside the thylakoids. In the process of photosynthesis there are two types of reaction ie; Light reaction or Photochemical reaction and Dark reaction or Biosynthetic reaction. Each smallest unit of pigment molecules in the thylakoids which is capable of carrying out the light reaction is said to be Photosynthetic unit or PSU or Quantasomes. The granum is the site for photochemical reaction and the stroma is the site for dark reaction in photosynthesis. These chloroplast are located at the outer margins ie; periphery of the cytoplasm with their broader surfaces parallel to the cell wall of the mesophyll cells.

17 Checking for understanding 1. Chloroplast membrane is made up of. (Lipoprotein, Cellulose, Chitin) 2. The space inside the chloroplast is filled with a protienaceous fluid called. (Grana, Stroma, Thylakoid) 3. The number of membrane bound sac like structure Embedded in the stroma are. (Grane, Thylakoid or Lamellae, Stroma thylakoid) 4. The site for light reaction is. (Grana, Stroma) 5. The site for dark reaction is. (Grana, Stroma). 6. Each small unit of pigment molecule capable of carrying out photosynthesis are called or. (Stroma or Grana, Stroma thylakoid or Grana thylakoid, Photosynthetic unit of Quantasome) Guided Practice 1. Chloroplast membrane is lipo-proteinaceous in nature. 2. The space inside the chloroplast is filled with a proteinaceous fluid called the stroma. The stroma contains DNA, Ribosomes and Enzymes for carbon assimilation. 3. The number of membrane bound-sac like structure embedded in the stroma is called Thylakoid or Lamellae. The thylakoid are seen in groups, each group is known as Granum. Each thylakoid in a granum is called Grana thylakoid and the

18 thylakoid which interconnects the adjacent grana is called Stroma thylakoid or Fret or Intergranal thylakoid. 4. The site for light reaction or photochemical reaction is Granum. 4. The site for dark reaction or biosynthetic reaction is Stroma. 6. Each small unit of pigment molecule capable of Carrying out photosynthesis is called photosynthetic unit of quantosomes. Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. Independent practice And Closure of the Lesson 1. Describe the structure of chloroplast. 2. What are quantasomes? 3. How many types of reactions are in the process of photosynthesis? Name them? 4. Why light reaction takes place only in the granum of chloroplast? 5. Define Fret. 6. Why chloroplasts are located at the periphery of the cytoplasm?

19 CORRECT ANSWER FOR LESSON 3 1. The chloroplast is a two unit membraneous structure. Each membrane is lipo-proteinaceous in nature. The space in between the two membranes is known as periplastidial space. The space inside the chloroplast is filled with a proteinaceous fluid called the stroma. The stroma contains DNA, ribosomes and enzymes for carbon assimilation. A number of membrane bound sac like structure are embedded in the stroma called thylakoids or lamellae. The thylakoid are seen in groups. Each group is called granum. Each thylakoid in a granum is called grana thylakoid and the thylakoid which interconnect the adjacent granum is called stroma thylakoid or fret or intergranal thylakoid. 2. The green pigment chlorophyll are seen as units inside the thylakoid. Each small unit of pigment molecules capable of carrying out photosynthesis is called quantasomes or photosynthetic unit. 3. There are two types of reaction in the process of photosynthesis they are light reaction or photochemical reaction and dark reaction or biosynthetic reaction. 4. For light reaction photochemical unit or quantasomes are required and these quantasomes are seen in the granum. So light reaction takes place in the granum of chloroplast. 5. The thylakoid which interconnects the adjacent granum is called the stroma thylakoid or fret or intergranal thylakoid. 6. Chloroplasts are located in the periphery of the cytoplasm because it helps in the diffusion of Co2 required for photosynthesis and in the easy harvesting of solar energy.

20 LESSON - 4 PHOTOSYNTHETIC PIGMENT CHLOROPHYLLa The objectives of the lesson: 1. The pupil tries to understand the importance of pigments in photosynthesis. 2. The pupil acquires the knowledge of photosynthetic pigments. 3. The pupil analyses the different types of photosynthetic pigment. 4. The pupil generalizes the importance of Chlorophyll a molecule. 5. The pupil evaluates the importance of Chlorophyll a molecule in the process of photosynthesis. Anticipatory set or Introduction In the earlier lesson you have seen about the photosynthetic unit. Here in this chapter learn about the pigment molecule in the photosynthetic unit. Here the importance of Chlorophyll a molecule is given with explanation. Learn about the universal photosynthetic unit. Teacher presents the lesson in different steps: Input or Procedure (1). Small steps with clear definitions. (2). Small questions are given for checking understanding. (3). In guided practice answers for the questions in the previous phase is give with explanation. (4). Independent practice is given with the closure of the lesson.

21 For photosynthesis light energy should be absorbed by some pigments. Here a pigment is a molecule that absorbs light of specific wave length in the visible spectrum. You can learn about the visible spectrum in the coming lesson. The photosynthetic pigments in higher plants are divided into Chlorophylls and Carotenoids. In this chapter we can deal with Chlorophylls. The chlorophylls are green pigments. Many type of chlorophylls are known, they are Chlorophyll a, Modelling Chlorophyll b, Chlorophyll c, Chlorophyll d, Chlorophyll e, bacteriochlorophyll and bacterioviridin. Of these Chlorophyll a is widely distributed in all autotropic plants. The photochemical reaction of photosynthesis takes place only in Chlorophyll a. The term Chlorophyll was given by Pelletier and Cavento. Chlorophyll a molecules are of different types. Some of them are Chlorophyll a 673, Chlorophyll a 683, P680, P700 etc. Chlorophyll a is found in all photosynthetic organisms except bacteria. Hence Chlorophyll a is known as universal photosynthetic pigment. Chlorophyll molecules absorb only red, blue and violet light in the visible spectrum. Chlorophyll molecules reflects green light in the visible spectrum. So Chlorophyll appears green. So the leaves also appear green in colour. The maximum rate of photosynthesis has been observed

22 in red light. In a photosynthetic unit all pigment molecules absorbs light energy and they transmit it to the neighboring molecule, finally it is focused to Chlorophyll a. The photochemical reaction takes place only in Chlorophyll a. Checking for understanding 1. is a molecule that absorbs light of Specific wave length in the visible spectrum. (Carbondioxide, Oxygen, Pigment) 2. The photochemical reaction takes place only in. (Chlorophyll b. Chlorophyll a, Carotenoids.) 3. Chlorophyll a reflects light in the visible spectrum. (Red, Green, Violet) 4. Maximum rate of photosynthesis has been observed in light. (Green, Blue, Red) 5. The term chlorophyll was given by. (Willstatler, Cavento, Stoll) Guided Practice 1. Pigment is a molecule that absorbs light of specific wave length in the visible spectrum. 2. The photochemical reaction takes place only in Chlorophyll a. 3. Chlorophyll a reflects green light in the visible spectrum. Red and Violet light are absorbed by Chlorophyll a molecule.

23 4. Maximum rate of photosynthesis takes place in red light. Green light is reflected by Chlorophyll a molecule. Blue light is absorbed by Chlorophyll a molecule. But maximum rate of photosynthesis takes place in red light. 5. The term chlorophyll was given by Cavento Willstatler and Stoll found out the structure of Chlorophyll molecule. Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. Independent practice And Closure of the Lesson 1. Define pigment. 2. Name the different types of photosynthetic pigments? 3. Name the different types of chlorophyll pigments? 4. Why Chlorophyll a is considered as the universal Photosynthetic pigment? 5. Why the leaves appear green in colour? 6. Does all the pigment molecules absorbs light energy in the photosynthetic unit.

24 CORRECT ANSWER FOR LESSON 4 1. A pigment is a molecule that absorbs light of a specific wave length in the visible spectrum. 2. The different types of photosynthetic pigments are chlorophylls and carotenoids. 3. The different types of chlorophyll pigments are Chlorophyll a, Chlorophyll b, Chlorophyll c, Chlorophyll d, Chlorophyll e, bacteriochlorophyll and bacterioviridin. 4. Chlorophyll a is found in all photosynthetic organisms except bacteria. Hence chlorophyll is known as universal photosynthetic pigment. 5. Chlorophyll molecules reflects green light in the visible spectrum. So Chlorophyll appears green. This is why leaves also appear green. 6. All the pigment molecules absorbs light energy and they transmit to the neighbouring molecule, finally it is focused to Chlorophyll a.

25 LESSON - 5 STRUCTURE OF CHLOROPHYLLa AND CHLOROPHYLLb MOLECULE The objectives of the lesson: 1. The pupil acquires the knowledge about Chlorophyll a and Chlorophyll b molecules. 2. The pupil understands the differences between Chlorophyll a and Chlorophyll b molecules. 3. The pupil develops the skill of observing, describing and classifying the difference between the molecules. 4. The pupil develops the elements of creativity such as visualizing and combining the facts in a lateral thinking. 5. The pupil develops proper attitude. Anticipatory set or Introduction Teacher presents the topic with the help of a diagram. By showing the molecular structure of Chlorophyll a and Chlorophyll b students tries to differentiate the two molecules. Teacher presents the topic with explanation. Teacher presents the topic: (1). With the help of molecular structure of Chlorophyll a and Chlorophyll b molecules. (2). Teacher tries to check the understanding of students with the help of multiple choice questions. (3). Guided practice is given.

26 Input or Procedure (4). In independent practice small questions are given. The Students should try to answer the questions by themselves. (5). If the students want to check the answers, correct answers are give in another file. The structure of Chlorophyll was first studied by Willstatler, Stoll and Fisher in The basic structure of all Chlorophyll molecules is Modelling Here if we analyse the structure, all Chlorophyll molecules is a porphyrin skeleton in which 4 pyrrole (tetrapyrrole) rings linked together by methane groups form a ring system. The centre of tetrapyrole is occupied

27 by a central core of magnesium (Mg 2 +). 2 covalent and 2 Co-ordinate bonds bind the Mg atom with the pyrrole rings. A lengthy hydrocarbon tail or side chain is attached to the porphyrin ring. It is called the phytol. So Chlorophyll has tadpole like structure. The phytol tail is composed of insoluble carbon and hydrogen atoms. This tail helps to fix the Chlorophyll molecule with the thylakoids in the Chloroplast. Porphyrin head is hydrophilic ie; water loving and phytol tail is lipophilic ie; fat loving. Chlorophyll a and Chlorophyll b structurally differ in the nature of groups attached. In Chlorophyll a a methyl group ( -CH 3 ) and in Chlorophyll b an aldehyde group ( -CHO ) are attached to the 3 rd carbon of the 2 nd pyrrole ring in the prophyrin head. The CHO group in Chlorophyll b increases the blue light absorption and decreases the red light absorption peak. Here see the difference between Chlorophyll a and Chlorophyll b molecules.

28 Difference between the two molecules is in the carbon group, ie; attached to the 3 rd carbon of the 2 nd pyrrole ring in the porphyrin head. Because of this difference the empirical formula also changes.

29 The empirical formula of Chlorophyll a is C 55 H 72 O 5 N 4 Mg The empirical formula of Chlorophyll b is C 55 H 70 O 6 N 4 Mg Chlorophyll a is blue green where as Chlorophyll b is olive green. Both are insoluble in organic solvents like alcohol, acetone etc. Molecular weight of Chlorophyll a is 873 and Chlorophyll b is 907. Chlorophyll a is more soluble in petroleum ether but Chlorophyll b is more soluble in methyl alcohol. Checking for understanding 1. The centre of tetrapyrrole is occupied by a central core of. (Mg, Mn,C) 2. A lengthy hydrocarbon tail or side chain attached to the prophyrin ring is called. (Thylakoid, Phytol, Aldehyde) 3. In Chlorophyll a molecule is attached to the 3 rd carbon of the 2 nd pyrrole ring. (Aldehyde, Methyl group, Water) 4. CHO group in Chlorophyll b increases the absorption. (Blue, Green, Red) 5. The empirical formulae of Chlorophyll b is. (C 55 H 72 O 5 N 4 Mg, C 55 H 71 O 6 N 4 Mg, C 55 H 70 O 6 N 4 Mg) 6. The colour of Chlorophyll b molecule. (Blue green, Olive green, Green) 7. Chlorophyll a is more soluble in. (Methyl alcohol, Petroleum ether, Acetone) 8. Molecular weight of Chlorophyll a molecule is. (907, 906, 873)

30 Guided Practice 1. The centre of tetrapyrrole is occupied by a central core of Mg. 2. A lengthy hydrocarbon tail or side chain attached to the prophyrin ring is called Phytol. 3. In Chlorophyll a molecule methyl group is attached to the 3 rd carbon of the 2 nd pyrrole ring. Aldehyde group is attached in Chlorophyll b molecule. 4. CHO group in Chlorophyll b increases the blue light absorption and decreases the red light absorption peak. 5. The empirical formula for Chlorophyll b molecule is C 55 H 70 O 6 N 4 Mg. The empirical formula for Chlorophyll a molecule is C 55 H 72 O 5 N 4 Mg. 6. The colour of Chlorophyll b molecule is Olive green. Blue green is the colour of Chlorophyll a molecule. 7. Chlorophyll a is more soluble in Petroleum ether. Chlorophyll b is more soluble in Methyl alcohol. 8. Molecular weight of Chlorophyll a molecule is 873. Molecular weight of Chlorophyll b molecule is 907. Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. 1. Explain the structure of Chlorophyll molecule. 2. State the difference between Chlorophyll a and Chlorophyll b in a chart form.

31 Independent practice And Closure of the Lesson 3. Give the empirical formula for Chlorophyll a and Chlorophyllb molecule. 4. What do you mean by hydrophilic? 5. Why maximum rate of photosynthesis doesn t takes place in Chlorophyllb molecule?

32 CORRECT ANSWER FOR LESSON 5 1. The basic structure of all Chlorophyll molecules is a prophyrin skeleton in Which 4 pyrrole (tetrapyrrole) rings linked together by methane groups form a ring system. The centre of tetrapyrrole is occupied by a central core of magnesium. Two covalent and two Co-ordinate bonds binds the Mg atom with the pyrrole rings. A lengthy hydrocarbon tail or side chain is attached to the prophyrin ring. It is called the phytol tail is composed of insoluble carbon and hydrogen atom. This tail helps to fix the Chlorophyll molecule with the thylakoids. 2. Chlorophyll a Chlorophyll b It is a primary photosynthetic pigment It is an accessory pigment. Molecular weight is 873 Molecular weight is 907. Blue green in pure state. Olive green in pure state. Empirical formula is C 55 H 72 O 5 N 4 Mg. Empirical formula is C 55 H 70 O 6 N 4 Mg It bears methyl group It bears aldehyde group More soluble in Petroleum ether. More soluble in Methyl alcohol. 3. The empirical formula for Chlorophyll a is C 55 H 72 O 5 N 4 Mg and the empirical formula for Chlorophyll b is C 55 H 70 O 6 N 4 Mg. 4. Hydrophilic is water loving molecules. 5. Because of CHO group in Chlorophyll b molecule blue light absorption is increased where as red light absorption is decreased. Only on the red light absorption peak maximum rate of photosynthesis takes place.

33 LESSON - 6 CAROTENOIDS The objectives of the lesson: 1. The pupil develops the knowledge of carotenoids. 2. The pupil understands the functions of carotenoids. 3. The pupil develops the skill of observation and classifying the different types of photosynthetic pigment. 4. The pupil visualizes the functions of carotenoids. 5. The pupil evaluates the importance of carotenoids. Anticipatory set or Introduction The topic carotenoids is presented with examples and explanation. This topic is generally easy to study. So study the lesson carefully. The lesson is presented in different stages: Input or Procedure (1). The lesson is given with explanations and examples. (2). For checking understanding, small multiple choice questions are given. (3). In guided practice, answers with explanation for previous stage is given. (4). In independent practice, open ended questions are given with closure of the lesson. (5). Correct answers for the questions in independent practice is given in another file.

34 Carotenoids include the orange pigment Carotene and the yellow pigment Xanthophyll or Carotenol. Carotenes are named after carrot in which they are abundant. These carotenes are responsible for the colour of Pumpkin, Red Pepper, Tomato etc. The important carotenes are β Carotenes. Xanthophyll are more abundant than carotenes. The yellow colour autumn leaves are due to the common Xanthophyll, Lutein. Modelling Carotenoids are present in all higher plants and in several lower plants. Carotenoids absorb blue and green lights in the visible spectrum. The general formula of Carotene is C 40 H 56. The general formula of Xanthophyll is C 40 H 56 O 2. Phycobilins are another group of photosynthetic pigment found in red algae and cyanobacteria (blue-green algae) Red algae contain red pigment, called Phycoerythrin and Cyanobacteria contain blue pigment called Phycocyanin. Both are photosynthetic water-soluble pigments.

35 FUNCTIONS OF CAROTENOIDS ARE: 1. Carotenoid molecules absorb light energy and they Transmit it to the neighbouring pigment molecules in the photosynthetic unit. 2. Protect the Chlorophyll molecules from photooxidation by picking up nascent O 2 and converting it into harmless molecular stage. Checking for understanding 1. Xanthophyll comes under the group. (Chlorophyll, Carotenoids, Phycobilins) 2. The general formula of carotene is. (C 40 H 56 O 2, C 40 H 56 O, C 40 H 56 ) 3. group of photosynthetic pigment found in Red algae and Cyanobacteria. (Chlorophyll, Carotenoids, Phycobilins) 4. Red algae contains. (Phycoerythrin, Phycocyanin, Xanthophyll) 5. The general formula of Xanthophyll is. (C 40 H 56 O 2, C 40 H 56 O, C 40 H 56 ) Guided Practice 1. Xanthophyll comes under the group carotenoids. Chlorophyll is the universal photosynthetic pigment. Phycobilins are another group of photosynthetic pigment found in Red algae and Cyanobacteria. 2. The general formula of Carotene is C 40 H Phycobilins are group of photosynthetic pigment found in red algae or cyanobacteria.

36 4. Red algae contain Phycoerythrin. Phycocyanin is seen in blue green algae or cyanobacteria. 5. The general formula for Xanthophyll is C 40 H 56 O. 2 Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. Independent practice And Closure of the Lesson 1. What are carotenoids? 2. Which pigment is responsible for the yellow color of autumn leaves? 3. What are the functions of Carotenoids? 4. What are Phycobilins? 5. Why Carotenoids appears in orange and yellow colour other than green colour? 6. Which pigment is responsible for the colour of Pumpkin, Tomato etc?

37 CORRECT ANSWER FOR LESSON 6 1. Carotenoids are photosynthetic pigments. Carotenoids include the orange pigment, carotene and the yellow pigment Xanthophyll 2. Lutein, a common Xanthophyll pigment is responsible for the yellow colour Of autumn leaves. 3. (a) Carotenoids molecules absorb light energy and they transmit it to the neighbouring pigment molecules. (b) Protect the chlorophyll molecules from photo-oxidation by picking up nascent O 2 and converting it into harmless molecular stage. 4. Phycobilins are another group of photosynthetic pigments found in red algae and cyanobacteria. 5. Carotenoids doesn t appear in green colour because Carotenoids absorbs green and blue light in the visible spectrum. Orange and yellow light are reflected. So Carotenoids appear orange and yellow in colour. 6. Carotenes are responsible for the color of Pumpkin and Tomato.

38 LESSON - 7 PHOTOSYNTHETIC UNIT The objectives of the lesson: 1. The pupil acquires the knowledge of photosynthetic unit. 2. The pupil understands the importance of photosynthetic unit. 3. The pupil analyses the functions of photosynthetic unit. 4. The pupil visualizes the importance of Chlorophyll a in the photochemical reaction. 5. The pupil organizes and evaluates the importance of chlorophyll a molecules in the process of photosynthesis. Anticipatory set or Introduction Teacher presents the lesson in small steps so that the students can understand the significance of photosynthetic unit in the process of photochemical reaction. The lesson is presented in different stages: Input or Procedure (1). The lesson photosynthetic unit is given in small steps with maximum explanation. (2). For checking understanding, small multiple choice questions are given. (3). In guided practice, the correct answers for the questions in the previous stage is given with explanation. (4). Independent practice is provide with the closure of the lesson. Here open ended questions are given.

39 (5). Correct answers for the questions in independent practice is given in another file. If the students are interested they can check for correct answers. The smallest group of pigment molecules and enzymes, participating in a photochemical reaction is called Photosynthetic unit or PSU or quantasomes. It was first isolated by Park and Biggins in Each photosynthetic unit has a Reaction Centre and a light harvesting pigment molecule. First we can see about the Reaction Centre. Reaction centre consist of a special Chlorophyll a molecule which absorbs long wave light energy. It is also called Photo centre or trap centre. There are 3 different types of reaction centre. They are Modelling P 700, P 680, P 870. P 700 means Chlorophyll a molecules with an absorption peak around 700nm. P 680 means Chlorophyll a molecule with an absorption peak around 680nm. P 870 means bacteriochlorophyll molecule with an absorption peak around 870nm. The Reaction centre is surrounded by a number of Light harvesting pigment molecules. The Photo centre requires the help of Light harvesting pigment molecules in the absorption of light energy. Second is the Light harvesting pigment molecule.

40 These are those pigment molecules which absorb light energy of different wave lengths and transfer it to the neighbouring pigment molecules. Finally the light energy is focused on to the Reaction Centre. The Photochemical reaction takes place only in the Reaction Centre. The Light harvesting pigment molecule is of two types. They are Core Molecules and Antenna Molecules. Core Molecules: They are pigment molecules which lie around the reaction centre. The number of core molecule is small, about They are usually Chlorophyll a molecule. Antenna Molecules : They are pigment molecules which lie around the core molecules. The antenna molecules are usually in number. These molecules include various Chlorophyll molecules and carotenoid molecules. They absorb light energy of

41 different wave lengths but shorter than that of Photo centre or Reaction centre. The chloroplast pigment can be extracted and separated by Paper Chromatography. Checking for understanding 1. Photosynthetic unit was isolated by. (Pelletier and Cavento, Willstatler and Fisher, Park and Biggins) 2. The Chlorophyll a molecules which absorbs long wave light energy is called. (Light harvesting molecules, Photo centre, Stroma thylakoid of Fret) 3. is a bacteriochlorophyll. (P 700, P 680, P 870 ) 4. The Photochemical reaction takes place only in the. (Light harvesting molecules, Photo centre, Periplastidial) 5. The pigment molecules which lie around the reaction centre is. (Antenna molecule, Core molecule, Trap centre) 1. Photosynthetic unit was isolated by Park and Biggins. Pelletier and Cavento coined the term chlorophyll. Willstatler Fisher and Stoll studied the structure of chlorophyll. 2. The chlorophyll a molecule which absorbs long wave

42 Guided Practice light energy is called Photo centre. Light harvesting molecules also absorbs light energy of different wave length lesser than reaction centre. Stroma thylakoid is seen in chloroplast. It is the interconnection between the adjacent grana. 3. P 870 is a bacteriochlorophyll. P 700 is chlorophyll a molecule with an absorption peak around 700nm. P 680 is also a chlorophyll a molecule with an absorption peak 680nm. 4. The Photochemical reaction takes place only in the Photo centre. Photo centre or Trap centre or Reaction centre is the only molecule which absorbs light energy of long wave length. 5. The pigment molecules which lies around the reaction centre is Core molecule. Antenna molecules are pigment molecules which lie around the core molecule. Trap centre is the another name for Reaction centre or Photo centre. Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. 1. Differentiate between Reaction centre and Light harvesting pigment molecule. 2. Why the Photochemical reaction takes place only in

43 Independent practice And Closure of the Lesson the reaction centre? 3. What are the different types of Light harvesting pigment molecules? 4. What is the function of Light harvesting pigment molecule? 5. Differentiate between Core molecule and Antenna molecule.

44 CORRECT ANSWER FOR LESSON 7 1. Reaction centre is a special chlorophyll a molecules which absorbs long wave light energy. a. Photochemical reaction takes place only in the Reaction centre. Light harvesting pigment molecules are those pigment molecules which absorbs light energy of different wave lengths and transfer it to the neighbouring pigment molecules and finally to the Reaction centre. b. Photochemical reaction doesn t takes place in light harvesting pigment molecule. 2. For Photochemical reaction to takes place light energy of high wave length is required and the light energy of high wave length is only absorbed by the reaction centre. So photochemical reaction takes place only in the reaction centre. 3. The different types of Light harvesting pigment molecules are Core molecule and Antenna molecules. 4. The function of Light harvesting pigment molecule is to absorb light energy of different wave lengths shorter than that of reaction centre and transferring it to neighbouring pigment molecule are finally to the reaction centre. 5. Core Molecules: a. Core molecules are the molecules which lie around the Reaction centre. b. The number of core molecule is small ie; c. Core molecules are usually chlorophyll a molecules. Antenna Molecules: a. Antenna molecules are the molecules which lie around the core molecule. b. Number of antenna molecule is large ie; c. It is usually various Chlorophyll molecules and carotenoid molecules.

45 LESSON - 8 NATURE OF LIGHT The objectives of the lesson: 1. The pupil acquires the knowledge about the Nature of Light. 2. The pupil tries to understand about the solar spectrum. 3. The pupil analyses the importance of visible spectrum in the importance of Photosynthesis. 4. The pupil organizes and classifies the new knowledge. 5. The pupil evaluates the function of Solar spectrum. Anticipatory set or Introduction Teacher explains the nature of light with the help of a diagram. The content is presented in simple language and in small frames. Read the content clearly, try to understand, go through the questions and answers till you are confident. The lesson is presented in different stages: Input or Procedure (1). The content with the help of diagram. (2). Small multiple choice questions are give for understanding. (3). Guided practice is given in the model of correct answers for the questions in the previous stage. (4). Independent practice is given with the closure of the lesson. (5). Correct answers for the questions in the independent practice is given in another file.

46 Sun is the ultimate source of all radiations. All the radiation emitted by sun constitute the Solar spectrum. The radiation from sun is electromagnetic in character. So these radiations are called electromagnetic radiation and the spectrum electromagnetic spectrum. The Solar spectrum consists of different types of radiations with different wave length. SOLAR SPECTRUM Modelling From the diagram you can understand that wave length of visible spectrum is 390nm to 760nm. This visible part in the solar spectrum is known as Visible Spectrum. A beam of visible spectrum transmitted through a prism consists of seven colours called VIBGYOR ie; Violet, Indigo, Blue, Green, Yellow, Orange and Red.

47 Each colour in the VIBGYOR has a different range of wavelength. Violet has the lowest wave length and the Red has the highest wave length in the Visible spectrum. From the diagram, try to understand the wave length of each colour in the Visible spectrum. The radiation with wave length above 760nm includes infra red radiation and radio waves. The radiation with wave length below 390nm includes Ultra-Violet radiation, X-Rays, Gamma Rays and Cosmic Rays. Photosynthetic pigment molecules absorb the light rays with wave length 400nm to 700nm in the visible spectrum. The portion of the Visible spectrum of light between 400nm to 700nm is called Photosynthetically Active Radiation (PAR). The light rays (visible rays) travel as streams of minute particles. Each light particle is called Photon. The energy contained in an individual photon is said to be Quantum. When visible light falls on the pigment molecule only certain wave length are absorbed by the pigment molecule, the rest is reflected. The absorbed wave length are to specific that they bring about certain Photochemical reactions.

48 Checking for understanding 1. All radiations emitted by sun constitute the. (Solar spectrum, Ultra violet spectrum, Infrared spectrum) 2. The wave length of visible spectrum ranges from. (10nm to 390nm, 390nm to 760nm, 760nm to 1,00,000nm) 3. The portion of the Visible spectrum of light between 400nm and 700nm is called. (Photo centre, Photosynthetic unit, Photosynthetically active radiation) 4. Each light particle is called. (Proton, Neutron, Photon) 5. The energy contained in an individual photon is called. (Neutron, Quantum, Electron) Guided Practice 1. All radiation emitted by sun constitute the Solar spectrum. 2. The wave length of visible spectrum ranges from 390nm to 760nm. 10nm to 390nm is Ultra violet rays. 760nm to 1,00,000nm is Infra red rays. 3. The portion of the visible spectrum of light between 400nm to 700nm is called Photsynthetically active radiation. Photo centre is the reaction centre ie; a Chlorophyll a molecule which absorbs long wave light energy. Photo synthetic unit is the smallest group of pigment

49 molecules, participating in a Photochemical reaction. 4. Each light particle is called Photon. 5. The energy contained in an individual photon is called Quantum. Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answers are correct. Independent practice And Closure of the Lesson 1. Why Solar spectrum is known as electromagnetic spectrum? 2. What is visible spectrum? 3. Which all colours are there in visible spectrum. Explain with there wave lengths. 4. What are Photosynthetically active radiation? 5. Define Photon. 6. Define Quantum.

50 CORRECT ANSWER FOR LESSON 8 1. The radiations in the Solar spectrum is electro magnetic in character. Hence the Solar spectrum is called Electro magnetic spectrum. 2. The radiation which ranges from 390nm to 700nm is called Visible spectrum. 3. The colours in the Visible spectrum is VIBGYOR ie; Violet, Indigo, Blue, Green, Yellow, Orange and Red. The wave length of Violet - 390nm to 430nm Indigo - 430nm to 470nm Blue - 470nm to 500nm Green - 500nm to 560nm Yellow - 560nm to 600nm Orange - 600nm to 650nm Red - 650nm to 760nm 4. Photosynthetic pigment molecules absorb the light rays with wave length 400nm to 700nm. The portion of visible spectrum of light between 400nm to 700nm is called Photosynthetically Active Radiation (PAR). 5. Each light particle is known as Photon. 6. The energy contained in a individual photon is called Quantum.

51 LESSON - 9 ABSORPTION AND ACTION SPECTRUM The objectives of the lesson: 1. The pupil acquires the knowledge of Absorption and action spectrum. 2. The pupil understands the concept. 3. The pupil analyses the importance of Absorption and Action spectrum. 4. The pupil organizes, evaluates and thus classifies the difference between Absorption and Action spectrum Anticipatory set or Introduction Input or Procedure The teacher explains the concept of Absorption and Action spectrum with the help of the diagram. The concept is explained in simple language and for further clarification the graphical representation of Absorption and Action spectrum are given. The lesson is prepared in different steps: (1). The concept is given in simple language. For clear Understanding graphical representation of Absorption and Action spectrum is given. (2). For checking understanding small multiple choice questions are given. (3). In guided practice the correct answer for the questions in the previous step is given with explanation. (4). Independent practice and closure of the lesson is given with small open ended questions. (5). The correct answers for the questions in the independent practice is given in another file.

52 From the previous lesson you have learnt that Chloroplast pigments are responsible for the Absorption of light. A particular pigment absorbs light rays with different wave length. For example; Chlorophyll a absorbs blue and red lights in the visible spectrum. The amount of light absorbed by a pigment can be plotted. Modelling The graphical representation of the absorption maxima against wave length is called Absorption spectrum.

53 Action spectrum Photosynthesis takes place in visible light ranging from 400nm to 700nm wave length. It does not take place at the same rate with other wave length. Therefore, the rate of Photosynthesis at different wave length is measured and plotted by amount of Action ie; O 2 evolved and Co 2 utilisation etc. This graphical representation of rate of Photosynthesis against the wave length is called Action spectrum. In 1882, T.W.Engelmann plotted the first action spectrum of photosynthesis using green algae. The maximum rate of Photosynthesis occurs with red light of the visible spectrum.

54 Checking for understanding 1. pigment is responsible for the absorption of light. (Chlorophyll, Xanthophyll, Carotenoid) 2. The graphic representation of the absorption maxima against wave length is called. (Action spectrum, Absorption spectrum, Visible spectrum) 3. The graphical representation of the rate of photosynthesis against the wave length is called. (Action spectrum, Absorption spectrum, Visible spectrum) 4. Maximum rate of photosynthesis takes place in light. (Blue, Red, Green) 5. The rate of photosynthesis is measured by the amount of action of. (Co 2 utilisation, O 2 utilisation) Guided Practice 1. Chlorophyll pigment is responsible for the absorption of light. 2. The graphic representation of the absorption maxima against wave length is called Absorption spectrum. 3. The graphic representation o rate of

55 photosynthesis against the wave length is called Action spectrum. 4. Maximum rate of photosynthesis takes place in Red light. 5. The rate of photosynthesis is measured by the amount of action of Co 2 utilisation. Answer the following questions by yourself. If you want to check whether it is correct or wrong, you can go to another file and see whether your answer are correct. Independent practice And Closure of the Lesson 1. Explain Absorption spectrum with graphical representation? 2. What is Action spectrum? Explain with graphical represention. 3. How does the rate of photosynthesis measured? 4. Why does maximum rate of photosynthesis takes place in red light?

56 CORRECT ANSWER FOR LESSON 9 1. The graphical representation of the absorption maxima against wave length is called Absorption spectrum. The percentage of absorption is plotted on the Y axis and wave length is plotted on the X axis. 2. The graphical representation of rate of photosynthesis against the wave length is called Action spectrum.

57 3. The rate of photosynthesis is measured by the amount of O 2 evolved and Co 2 utilisation. 4. Maximum rate of photosynthesis takes place at maximum wave length. Red light has maximum wave length so maximum rate of photosynthesis takes place at red light.

58 APPENDIX II LESSON TRANSCRIPTS FOR LEARNING LESSON TRANSCRIPT 1 PHOTOSYNTHESIS Author: Mary Sindhu J Subject: Biology School: Standard: Autotrophic plants prepare their own food material through the process called Photosynthesis. Photosynthesis is the process of synthesis of carbohydrates from carbondioxide and water in the presence of sunlight and chlorophyll. It is the most important synthetic process on earth. Here the solar energy is fixed in the form of chemical energy ie; the plants have the capacity of capturing light energy from the sun and converting it into chemical energy. Here the kinetic energy of sunlight is transformed into chemical energy and stored in the carbohydrate molecules. This chemical energy is used for the growth and development of all forms of life in the universe.

59 Approximately 90% of the world s photosynthesis is carried out by marine algae and fresh water algae and all animals depend on plants and their source of energy. Photosynthesis is considered as the natural physio-biological process of the world on which the existence of life in earth depends. So photosynthesis is the single most important biological process required for human existence. Checking for Understanding: 1. Photosynthesis is the process of synthesis of. (Carbohydrate, Fat) 2. During photosynthesis energy is converted into energy. (Light energy-chemical energy, Sound energy-chemical energy) 3. 90% of photosynthesis is carried out by and. (Marine algae & Fresh water algae, Animals & Zooplankton) 4. The natural physio-biological process of the world is. (Photosynthesis, Respiration)

60 LESSON TRANSCRIPT 2 CHLOROPLAST THE SITE FOR PHOTOSYNTHESIS Author: Mary Sindhu J Subject: Biology School: Standard: Photosynthesis is the process of synthesis of carbohydrate from Co 2 and water in the presence of sunlight and chlorophyll. 6CO H 2 O C 6 H 12 O 6 + 6H 2 O + 6O 2 Here the photosynthesis takes place in the green parts of the plant body such as leaves, green stems and in green floral parts etc. In leaves the photosynthesis takes place in the mesophyll tissues. Structure of Leaf

61 In the structure of a leaf the green tissues seen in between the upper and lower epidermis is the mesophyll tissue. The mesophyll is differentiated into palisade parenchyma and spongy parenchyma. Both these parenchyma cells contain the green plastid-chloroplast. These chloroplasts are the characteristic structure of green plants. The chloroplasts are green due to the presence of green pigment chlorophyll. Here the chloroplasts are considered as the seats of photosynthesis, they synthesis starch by using CO 2 and sunlight. So chloroplast is considered as the photosynthetic apparatus. The chloroplasts are distributed homogeneously in the cytoplasm of plant cell. Their diameter is about 5 to 8 µ. The size of the chloroplast varies from species to species. In green algae, the chloroplast has various shapes, example. Ribbon shaped (Spirogyra)

62 Star shaped (Zygnema) Girdle shaped (Ulothrix) Disc shaped (Caulerpa)

63 Reticulate shaped (Oedogonium) Cup shaped (Chlamydomanas) Checking for understanding: 1. Photosynthesis takes place only in. (Green parts, Flowers, Roots)

64 2. The green plastids seen in the cytoplasm are called. (Chloroplast, Palisade tissue, Vacuoles) 3. is considered as the photosynthetic apparatus. (Mesophyll tissue, Flowers, Chloroplast) 4. The diameter of the chloroplast varies from. (5-10 µ, 5-8 µ, 5-6 µ) 5. The shape of chloroplast in chlamydomonas is. (Star shaped, Girdle shaped, Cup shaped)

65 LESSON TRANSCRIPT 3 STRUCTURE OF CHLOROPLAST Author: Mary Sindhu J Subject: Biology School: Standard: Now we can see the structure of chloroplast. Structure of Chloroplast

66 The chloroplast is surrounded by two unit membrane. Each membrane is lipo-proteinaceous in nature. The space in between two membranes is known as periplastidial space. The space inside the chloroplast is filled with a proteinaceous fluid called Stroma. The stroma contains DNA, Ribosome s and Enzymes for carbon assimilation. The enzymes found in stroma are capable of utilizing ATP and NADPH 2 to produce carbohydrates. A number of membrane bound, sac like structure are embedded in the stroma. The structures are called the Thylakoids or Lamellae. The thylakoids are seen in groups. Each group is known as Granum. Each thylakoid in a granum is called the grana thylakoid. The thylakoid which interconnects the adjacent grana is called the stromathylakoid or fret or intergranal thylakoid. Each thylakoid is also a double membrane-bound structure. The green pigment molecules, chlorophyll are seen as units inside the thylakoids. In the process of photosynthesis there are two types of reaction ie; Light reaction or Photochemical reaction and Dark reaction or Biosynthetic reaction. Each smallest unit of pigment molecules in the thylakoids which is capable of carrying out the light reaction is said to be Photosynthetic unit or PSU or Quantasomes.

67 The granum is the site for photochemical reaction and the stroma is the site for dark reaction in photosynthesis. These chloroplast are located at the outer margins ie; periphery of the cytoplasm with their broader surfaces parallel to the cell wall of the mesophyll cells. Checking for understanding: 1. Chloroplast membrane is made up of. (Lipoprotein, Cellulose, Chitin) 2. The space inside the chloroplast is filled with a protienaceous fluid called. (Grana, Stroma, Thylakoid) 3. The number of membrane bound sac like structure Embedded in the stroma are. (Grane, Thylakoid or Lamellae, Stroma thylakoid) 4. The site for light reaction is. (Grana, Stroma) 5. The site for dark reaction is. (Grana, Stroma).

68 6. Each small unit of pigment molecule capable of carrying out photosynthesis are called or. (Stroma or Grana, Stroma thylakoid or Grana thylakoid, Photosynthetic unit of Quantasome)

69 LESSON TRANSCRIPT 4 PHOTOSYNTHETIC PIGMENT CHLOROPHYLL a Author: Mary Sindhu J Subject: Biology School: Standard: For photosynthesis light energy should be absorbed by some pigments. Here a pigment is a molecule that absorbs light of specific wave length in the visible spectrum. You can learn about the visible spectrum in the coming lesson. The photosynthetic pigments in higher plants are divided into Chlorophylls and Carotenoids. In this chapter we can deal with Chlorophylls. The chlorophylls are green pigments. Many type of chlorophylls are known, they are Chlorophyll a, Chlorophyll b, Chlorophyll c, Chlorophyll d, Chlorophyll e, bacteriochlorophyll and bacterioviridin. Of these Chlorophyll a is widely distributed in all autotropic plants. The photochemical reaction of photosynthesis takes place only in Chlorophyll a. The term Chlorophyll was given by Pelletier and Cavento. Chlorophyll a molecules are of different types. Some of them are Chlorophyll a 673, Chlorophyll a 683, P680, P700 etc. Chlorophyll a is found in all

70 photosynthetic organisms except bacteria. Hence Chlorophyll a is known as universal photosynthetic pigment. Chlorophyll molecules absorb only red, blue and violet light in the visible spectrum. Chlorophyll molecules reflects green light in the visible spectrum. So Chlorophyll appears green. So the leaves also appear green in color. The maximum rate of photosynthesis has been observed in red light. In a photosynthetic unit all pigment molecules absorbs light energy and they transmit it to the neighboring molecule, finally it is focused to Chlorophylla. The photochemical reaction takes place only in Chlorophylla. Checking for understanding: 1. is a molecule that absorbs light of Specific wave length in the visible spectrum. (Carbondioxide, Oxygen, Pigment) 2. The photochemical reaction takes place only in. (Chlorophyll b. Chlorophyll a, Carotenoids) 3. Chlorophyll a reflects light in the visible spectrum. (Red, Green, Violet)

71 4. Maximum rate of photosynthesis has been observed in light. (Green, Blue, Red) 5. The term chlorophyll was give by. (Willstatler, Cavento, Stoll)

72 LESSON TRANSCRIPT 5 STRUCTURE OF CHLOROPHYLL a AND CHLOROPHYLL b MOLECULE Author: Mary Sindhu J Subject: Biology School: Standard: The structure of Chlorophyll was first studied by Willstatler, Stoll and Fisher in The basic structure of all Chlorophyll molecule is

73 Here if we analyse the structure, all Chlorophyll molecules is a porphyrin skeleton in which 4 pyrrole (tetrapyrrole) rings linked together by methane groups from a ring system. The centre of tetrapyrole is occupied by a central core of magnesium (Mg 2 +). 2 covalent and 2 Co-ordinate bonds bind the Mg atom with the pyrrole rings. A lengthy hydrocarbon tail or side chain is attached to the porphyrin ring. It is called the phytol. So Chlorophyll has tadpole like structure. The phytol tail is composed of insoluble carbon and hydrogen atoms. This tail helps to fix the Chlorophyll molecule with the thylakoids in the Chloroplast. Porphyrin head is hydrophilic ie; water loving and phytol tail is lipophilic ie; fat loving. Chlorophyll a and Chlorophyll b structurally differ in the nature of groups attached. In Chlorophyll a a methyl group ( -CH 3 ) and in Chlorophyll b an aldehyde group ( -CHO ) are attached to the 3 rd carbon of the 2 nd pyrrole ring in the prophyrin head. The CHO group in Chlorophyll b increases the blue light absorption and decreases the red light absorption peak. Here see the difference between Chlorophyll a and Chlorophyll b molecules.

74

75 The only difference between the two molecules is in the carbon group, ie; attached to the 3 rd carbon of the 2 nd pyrrole ring in the porphyrin head. Because of this difference the empirical formula also changes. The empirical formula of Chlorophyll a is C 55 H 72 O 5 N 4 Mg The empirical formula of Chlorophyll b is C 55 H 70 O 6 N 4 Mg Chlorophyll a is blue green where as Chlorophyll b is olive green. Both are insoluble in organic solvents like alcohol, acetone etc. Molecular weight of Chlorophyll a is 873 and Chlorophyll b is 907. Chlorophyll a is more soluble in petroleum ether but Chlorophyll b is more soluble in methyl alcohol. Checking for understanding: 1. The centre of tetrapyrrole is occupied by a central core of. (Mg, Mn, C) 2. A lengthy hydrocarbon tail or side chain attached to the prophyrin ring is called. (Thylakoid, Phytol, Aldehyde) 3. In Chlorophyll a molecule is attached to the 3 rd carbon of the 2 nd pyrrole ring. (Aldehyde, Methyl group, Water)

76 4. CHO group in Chlorophyll b increases the absorption. (Blue, Green, Red) 5. The empirical formulae of Chlorophyll b is. (C 55 H 72 O 5 N 4 Mg, C 55 H 71 O 6 N 4 Mg, C 55 H 70 O 6 N 4 Mg) 6. The colour of Chlorophyll b molecule. (Blue green, Olive green, Green) 7. Chlorophyll a is more soluble in. (Methyl alcohol, Petroleum ether, Acetone) 8. Molecular weight of Chlorophyll a molecule is. (907, 906, 873)

77 LESSON TRANSCRIPT 6 CAROTENOIDS Author: Mary Sindhu J Subject: Biology School: Standard: Carotenoids include the orange pigment Carotene and the yellow pigment Xanthophyll or Carotenol. Carotenes are named after carrot in which they are abundant. These carotenes are responsible for the colour of Pumpkin, Red Pepper, Tomato etc. The important carotenes are β Carotenes. Xanthophyll are more abundant than carotenes. The yellow colour autumn leaves are due to the common Xanthophyll, Lutein. Carotenoids are present in all higher plants and in several lower plants. Carotenoids absorb blue and green lights in the visible spectrum. The general formula of Carotene is C 40 H 56. The general formula of Xanthophyll is C 40 H 56 O 2. Phycobilins are another group of photosynthetic pigment found in red algae and cyanobacteria (blue-green algae) Red algae contain red pigment, called Phycoerythrin and Cyanobacteria contain blue pigment called Phycocyanin. Both are photosynthetic watersoluble pigments.

78 Functions of Carotenoids are: 1. Carotenoid molecules absorb light energy and they transmit it to the neighbouring pigment molecules in the photosynthetic unit. 2. Protect the Chlorophyll molecules from photo-oxidation by picking up nascent O 2 and converting it into harmless molecular stage. Checking for understanding: 1. Xanthophyll comes under the group. (Chlorophyll, Carotenoids, Phycobilins) 2. The general formula of carotene is. (C 40 H 56 O 2, C 40 H 56 O, C 40 H 56 ) 3. group of photosynthetic pigment found in Red algae and Cyanobacteria. (Chlorophyll, Carotenoids, Phycobilins) 4. Red algae contain. (Phycoerythrin, Phycocyanin, Xanthophyll) 5. The general formula of Xanthophyll is. (C 40 H 56 O 2, C 40 H 56 O, C 40 H 56 )

79 LESSON TRANSCRIPT 7 PHOTOSYNTHETIC UNIT Author: Mary Sindhu J Subject: Biology School: Standard: The smallest group of pigment molecules and enzymes, participating in a photochemical reaction is called Photosynthetic unit or PSU or quantasomes. It was first isolated by Park and Biggins in Each photosynthetic unit has a Reaction Centre and a light harvesting pigment molecule. First we can see about the Reaction Centre. Reaction centre consist of a special Chlorophyll a molecule which absorbs long wave light energy. It is also called Photo centre or trap centre. There are 3 different types of reaction centre. They are P 700, P 680, P 870. P 700 means Chlorophyll a molecules with an absorption peak around 700nm. P 680 means Chlorophyll a molecule with an absorption peak around 680nm. P 870 means bacteriochlorophyll molecule with an absorption peak around 870nm.

80 The Reaction centre is surrounded by a number of Light harvesting pigment molecules. The Photo centre requires the help of Light harvesting pigment molecules in the absorption of light energy. Second is the Light harvesting pigment molecule. These are those pigment molecules which absorb light energy of different wave lengths and transfer it to the neighbouring pigment molecules. Finally the light energy is focused on to the Reaction Centre. The Photochemical reaction takes place only in the Reaction Centre. The Light harvesting pigment molecule is of two types. They are Core Molecules and Antenna Molecules.

81 Core Molecules: They are pigment molecules which lie around the reaction centre. The number of core molecule is small, about They are usually Chlorophyll a molecule. Antenna Molecules : They are pigment molecules which lie around the core molecules. The antenna molecules are usually in number. These molecules include various Chlorophyll molecules and carotenoid molecules. They absorb light energy of different wave lengths but shorter than that of Photo centre or Reaction centre. The chloroplast pigment can be extracted and separated by Paper Chromatography. Checking for understanding: 1. Photosynthetic unit was isolated by. (Pelletier and Cavento, Willstatler and Fisher, Park and Biggins)

82 2. The Chlorophyll a molecules which absorbs long wave light energy is called. (Light harvesting molecules, Photo centre, Stroma thylakoid of Fret) 3. is a bacteriochlorophyll. (P 700, P 680, P 870 ) 4. The Photochemical reaction takes place only in the. (Light harvesting molecules, Photo centre, Periplastidial) 5. The pigment molecules which lie around the reaction centre is. (Antenna molecule, Core molecule, Trap centre)

83 LESSON TRANSCRIPT 8 NATURE OF LIGHT Author: Mary Sindhu J Subject: Biology School: Standard: Sun is the ultimate source of all radiations. All the radiation emitted by sun constitute the Solar spectrum. The radiation from sun is electromagnetic in character. So these radiations are called electromagnetic radiation and the spectrum electromagnetic spectrum. The Solar spectrum consists of different types of radiations with different wave length. SOLAR SPECTRUM

84 From the diagram you can understand that wave length of visible spectrum is 390nm to 760nm. This visible part in the solar spectrum is known as Visible Spectrum. A beam of visible spectrum transmitted through a prism consists of seven colours called VIBGYOR ie; Violet, Indigo, Blue, Green, Yellow, Orange and Red. Each colour in the VIBGYOR has a different range of wavelength. Violet has the lowest wave length and the Red has the highest wave length in the visible spectrum. From the diagram, try to understand the wave length of each colour in the visible spectrum. The radiation with wave length above 760nm includes infra red radiation and radio waves. The radiation with wave length below 390nm includes Ultra- Violet radiation, X-Rays, Gamma Rays and Cosmic Rays. Photosynthetic pigment molecules absorb the light rays with wave length 400nm to 700nm in the visible spectrum. The portion of the Visible spectrum of light between 400nm to 700nm is called Photosynthetically Active Radiation (PAR).

85 The light rays (visible rays) travel as streams of minute particles. Each light particle is called Photon. The energy contained in an individual photon is said to be Quantum. When visible light falls on the pigment molecule only certain wave lengths are absorbed by the pigment molecule, the rest is reflected. The absorbed wave lengths are to specific that they bring about certain Photochemical reactions. Checking for understanding: 1. All radiations emitted by sun constitute the. (Solar spectrum, Ultra violet spectrum, Infrared spectrum) 2. The wave length of visible spectrum ranges from. (10nm to 390nm, 390nm to 760nm, 760nm to 1,00,000nm) 3. The portion of the Visible spectrum of light between 400nm and 700nm is called. (Photo centre, Photosynthetic unit, Photosynthetically active radiation) 4. Each light particle is called. (Proton, Neutron, Photon) 5. The energy contained in an individual photon is called. (Neutron, Quantum, Electron)

86 LESSON TRANSCRIPT 9 ABSORPTION AND ACTION SPECTRUM Author: Mary Sindhu J Subject: Biology School: Standard: From the previous lesson you have learnt that Chloroplast pigments are responsible for the Absorption of light. A particular pigment absorbs light rays with different wave length. For example; Chlorophyll a absorbs blue and red lights in the visible spectrum. The amount of light absorbed by a pigment can be plotted.

87 The graphical representation of the absorption maxima against wave length is called Absorption spectrum. Action spectrum Photosynthesis takes place in visible light ranging from 400nm to 700nm wave length. It does not take place at the same rate with other wave length. Therefore, the rate of Photosynthesis at different wave length is measured and plotted by amount of Action ie; O 2 evolved and Co 2 utilisation etc. This graphical representation of rate of Photosynthesis against the wave length is called Action spectrum.

88 In 1882, T.W.Engelmann plotted the first action spectrum of photosynthesis using green algae. The maximum rate of Photosynthesis occurs with red light of the visible spectrum. Checking for understanding: 1. pigment is responsible for the absorption of light. (Chlorophyll, Xanthophyll, Carotenoid) 2. The graphic representation of the absorption maxima against wave length is called. (Action spectrum, Absorption spectrum, Visible spectrum) 3. The graphical representation of the rate of photosynthesis against the wave length is called. (Action spectrum, Absorption spectrum, Visible spectrum) 4. Maximum rate of photosynthesis takes place in light. (Blue, Red, Green) 5. The rate of photosynthesis is measured by the amount of action of. (Co 2 utilisation, O 2 utilisation)

89 APPENDIX- III LESSON TRANSCRIPTS FOR VOICE CHATTING TECHNIQUE LESSON TRANSCRIPT I PHOTOSYNTHESIS Author : School : Subject : Standard : Content Objective In this lesson the significance of photosynthesis is explained. Teacher expresses the content with the help of examples and thought provoking questions. Stated objective Purpose or Goal of lesson (1). The pupil acquires the knowledge of photosynthesis. (2). The pupil understands the significance of photosynthesis. (3). The pupil analyses the process of photosynthesis as the important biological process. (4). The pupil organizes, evaluates and makes inferences on the importance of photosynthesis. Anticipatory set or Introduction Teacher gives the concept of photosynthesis and their significance through clear explanation. Input or Procedure The lesson is prepared in different phases: 1. Teacher presents the lesson in small steps. 2. Teacher guides the students to learn the lesson with divergent questions.

90 3. Teacher explains the questions through guided practice. 4. Students learn the lesson through thought provoking questions. Modelling Teacher presents the topic photosynthesis through small steps. Teacher expresses the content by using simple language. Checking for understanding Small multiple choice questions are asked to the students. So that the students can identify whether they have mastered the content. Guided Practice In guided practice the answers for the questions in the previous step is explained. If the students wish to hear the content once again the teacher explains the content once again in the phase. Independent practice And Closure of the Lesson In Independent practice small open ended questions are asked. Students should answer the questions without choice. The questions are: 1. Why photosynthesis is considered as a significant process? 2. What is photosynthesis? 3. During photosynthesis which energy is converted into chemical energy? 4. Which is the most important biological process required for human existence?

91 LESSON TRANSCRIPT 2 CHLOROPLAST THE SITE FOR PHOTOSYNTHESIS Author : School : Subject : Standard : Content Objective The students after learning the concept photosynthesis the concept chloroplast are explained. The importance of chloroplast and why chloroplast is considered as the photosynthetic apparatus is explained in this lesson. Stated objective Purpose or Goal of lesson (1). The pupil understands the importance of chloroplast in the process of photosynthesis. (2). The pupil identifies the structure of leaf and its importance. (3). The pupil analyses the importance of photosynthetic apparatus. (4). The pupil differentiates the different shapes of chloroplast. (5). The pupil synthesis the knowledge that size and shape of chloroplast varies from species to species. Anticipatory set or Introduction Teacher explains the position of chloroplast with the help of a diagram The structure of Leaf. Teacher explains the significance of chloroplast and why chloroplast is said to be the photosynthetic apparatus.

92 Input or Procedure The lesson is prepared in different steps: 1. Teacher explains the content in series of small steps. 2. Teacher checks the understanding of students with multiple choice questions. 3. Teacher explains the content once again in the guided practice. 4. Teacher makes the closure of lesson through Independent practice. Modelling Teacher explains where the chloroplast is present with the help of the diagram of structure of Leaf. Teacher explains why chloroplast is considered as the photosynthetic apparatus and explains that size and shape of chloroplast varies from species to species. To show various shape of chloroplast the teacher with the help of diagrams site the shape of chloroplast of some green algae. Checking for understanding Small multiple choice questions are asked to the students. So that the students can identify whether they have mastered the content. Guided Practice Here the teacher explains the answers for the questions in the previous step. Once again the teacher explains the content for the students through this page.

93 Independent practice And Closure of the Lesson In Independent practice the teacher ask small open ended questions such as 1. Why chloroplast is considered as the photosynthetic apparatus? 2. Why photosynthesis takes place in the green parts of the plant body? 3. Why photosynthesis doesn t takes place in the roots of the plants?

94 LESSON TRANSCRIPT 3 STRUCTURE OF CHLOROPLAST Author : School : Subject : Standard : Content Objective The pupil tries to understand the structure of Chloroplast. Students perceives the terms such as periplastidial space, stroma, grana, thylakoid, frets, photosynthetic unit or quantasomes. Stated objective Purpose or Goal of lesson The pupil understands the structure of chloroplast. (1) The pupil explains the importance of chloroplast. (2) The pupil analyses the role of chloroplast in the process of photosynthesis. (3) The pupil syntheses the knowledge about the function of chloroplast. Anticipatory set or Introduction The teacher presents the topic with the help of the diagram of chloroplast. The teacher explains the concept in simple language. Input or Procedure The lesson is prepared in different steps : (1) The lesson is presented with the help of a diagram. (2) Small questions are given for checking understanding. (3) Answers for the questions in the previous step are given.

95 (4) Independent practice with the closure of the lesson is given. Modelling The teacher explains various terms which is involved in the structure of chloroplast with the help of diagram. Teacher interacts with the students and through discussion the students tries to learn about photosynthetic unit or quantasomes, stroma, grana, and fret. Checking for understanding After explaining the structure of chloroplast for checking the students understanding teacher ask multiple choice questions. Guided Practice In guided practice if the students are unable to answer the questions in the previous stage the teacher explains the concept once again for the students in the question answer form. In Independent practice small open ended questions are asked. Students should answer the questions without choice. The questions are: Independent practice And Closure of the Lesson 1. Describe the structure of Chloroplast? 2. What are quatasomes? 3. Why light reaction takes place only in granum of chloroplast? 4. Why chloroplasts are located on the periphery of cytoplasm? 5. Define fret?

96 LESSON TRANSCRIPT 4 PHOTOSYNTHETIC PIGMENT - CHLOROPHYLL a Author : School : Subject : Standard : The student should understand the importance of pigments in the process of photosynthesis. Moreover Content Objective students should generalize the importance of chlorophyll a molecule and why chlorophyll a is considered as the Universal photosynthetic pigment. Stated objective Purpose or Goal of lesson (1). The pupil tries to understand the importance of pigments in photosynthesis. (2). The pupil acquires the knowledge of photosynthetic pigment. (3). The pupil analyses the different types of photosynthetic pigments. (4). The pupil generalizes the importance of chlorophyll a molecule. (5). The pupil evaluates the importance of chlorophyll a molecule in the process of photosynthesis. Anticipatory set or Introduction Here the teacher explains the content before the students with examples so that the students would understand the content thoroughly. The lesson is prepared in different phases: 1. Teacher presents the lesson in small steps with

97 Input or Procedure clear definitions. 2. Teacher guides the students to learn the lesson with divergent questions. 3. Teacher explains the questions through guided practice. 4. Students learn the lesson through thought provoking questions. Modelling The teacher presents the concept with clear definitions. Through discussion the new terms such as Universal photosynthetic pigment and visible spectrum are introduced before the students. Teacher with explanations presents the topic. Checking for understanding The teacher after explaining the concept asks question to check the understanding of the students. Small multiple choice questions are asked so that if the students had understood the concept can answer easily. Guided Practice After asking questions if the students didn t answer the questions the teacher explains the answers with suitable examples. Here in guided practice the teacher explains the concept once again for the students. In Independent practice small open ended questions are asked. If the students have analyzed the concept the students will be able to answer the questions. The questions are:

98 Independent practice And Closure of the Lesson 1. What is a pigment? 2. Name the different type of photosynthetic pigments. 3. Name the different types of photosynthetic Chlorophyll pigments. 4. Why chlorophyll a is considered as the universal photosynthetic pigment? 5. Why the leaves appear green in colour? 6. Does all the pigment molecules appear light energy in the photosynthetic unit?

99 LESSON TRANSCRIPT 5 STRUCTURE OF CHLOROPHYLL a AND CHLOROPHYLL b MOLECULE. Author : School : Subject : Standard : Content Objective Teacher introduces the molecular structure of chlorophyll a and chlorophyll b molecule with the help of the diagrams. The students should familiarize the terms such as tetrapyrrole, phytol, hydrophilic, lipophilic etc. The students should categorise the difference between chlorophyll a and Chlorophyll b molecule. Stated objective Purpose or Goal of lesson (1). The pupil acquires the knowledge about Chlorophyll a and Chlorophyll b molecules. (2). The pupil understands the differences between Chlorophyll a and Chlorophyll b molecules. (3). The pupil develops the skill of observing, describing and classifying the difference between the molecules. (4). The pupil develops the elements of creativity such as visualizing and combining the facts in a lateral thinking. (5). The pupil develops proper attitude.

100 Anticipatory set or Introduction Teacher explains the general structure of Chlorophyll molecule with the help of the diagram of the molecular structure of Chlorophyll molecule. After that the teacher presents the diagram of the molecular structure of Chlorophyll a and Chlorophyll b molecule from the diagrams the students should try to differentiate the two molecules. Input or Procedure The lesson is prepared in different steps: 1. Teacher explains the content with the help of molecular structure of Chlorophyll a and Chlorophyllb molecules. 2. Teacher checks the understanding of students with multiple choice questions. 3. Teacher explains the content once again in the guided practice. 4. Teacher makes the closure of lesson through Independent practice. Modelling First the teacher explains the structure of Chlorophyll molecule. Than by showing the molecular structure of the Chlorophyll molecule the teacher explains the terms such as tetrapyrrole and phytol tail. After that the teacher shows the diagram of the molecular structure of Chlorophyll a and Chlorophyllb molecule. The students by observing the diagrams should give the differences between the two molecule. The teacher gives the empirical formulae of Chlorophyll a and Chlorophyllb molecule. Checking for understanding For checking the understanding of the students the

101 teacher asks multiple choice questions. Guided practice After asking the questions the teacher would explain the content once again for the students for thorough understanding. Than the teacher explains the answers for all questions which was asked. Independent practice And Closure of the Lesson After mastering the content thoroughly through guided practice the teacher asks small open ended questions like, (1) Explain the structure of Chlorophyll molecule? (2) State the difference between Chlorophyll a and Chlorophyll b molecule. (3) What do you mean by hydrophilic? (4) Why maximum rate of photosynthesis doesn t takes place in Chlorophyll b molecule?

102 LESSON TRANSCRIPT 6 CAROTENOIDS Author : School : Subject : Standard : Content Objective The students should understand what are carotenoids and what are the different types of carotenoids? Why carrot has orange colour? Why during autumn the leaves become yellow in colour? The student tries to learn the general formulae of Carotenoid and Xanthophyll. Stated objective Purpose or Goal of lesson (1) The pupil develops the knowledge of Carotenoids. (2) The pupil understands the functions of Carotenoids. (3) The pupil develops the skill of observation and classifying the different types of photosynthetic pigment. (4) The pupil develops visualizes the functions of Carotenoids. (5) The pupil evaluates the importance of Carotenoids. Anticipatory set or Introduction The topic Carotenoid is generally easy for the students. The teacher presents the topic with examples and explanations.

103 Input or Procedure (1) The teacher presents the topic with examples and explanation. (2) Teacher asks certain divergent questions for checking the understanding of the students. (3) In guided practice the teacher with explanation gives the correct answers for the questions. (4) In independent practice section open ended questions are asked. Modelling The teacher explains the term Carotenoids and the different types of Carotenoids. The teacher introduces Beta carotenes and lutein. The teacher gives the general formulae for carotene and Xanthophyll. Teacher introduces the new concept Phycoblins. And explain the functions the functions of Carotenoids Checking for understanding For checking the understanding of the students the teacher asks multiple choice questions. Guided practice After asking the questions the teacher would explain the content once again for the students for thorough understanding. Than the teacher explains the answers for all questions which was asked.

104 Independent practice and closure of the lesson In Independent practice the teacher ask small questions like : (1) What are carotenoids? (1) Which pigment is responsible for the yellow colour of the autumn leaves? (2) What are the functions of Carotenoids? (3) What are Phycobilins? (4) Why Carotenoids appears in orange and yellow colour other than green colour? (5) Which pigment is responsible for the colour of Pumpkin, Tomato etc.

105 LESSON TRANSCRIPT 7 PHOTOSYNTHETIC UNIT Author : School : Subject : Standard : Content Objective Students should know about the photosynthetic unit. For that the teacher with the help of a diagram explains the concept of photosynthetic unit. The pupil should understand analyse and organize the concept. Stated objective Purpose or Goal of lesson Anticipatory set or Introduction (1) The pupil acquires the knowledge of photosynthetic unit. (2) The pupil understands the importance of photosynthetic unit. (3) The pupil analyses the functions of photosynthetic unit. (4) The pupil visualizes the importance of Chlorophyll a in the photochemical reaction. (5) The pupil organizes and evaluates the importance of Chlorophyll a molecules in the process of photosynthesis. Teacher presents the lesson with the help of a diagram. The student carefully observes the diagram and analysis the important parts in the diagram and should arrive at a conclusion. The lesson photosynthetic unit is given is small steps.

106 Input or Procedure (1) For checking understanding small questions are asked. (2) In guided practice the teacher explains the content once again to the students and clarifies the doubts. (3) In Independent practice small questions are asked to the students. (4) Here the teacher explains the correct answer to the students. Modelling The teacher explains the concept of photosynthetic unit in simple language so that everyone can grasp the concept easily. Teacher introduces the new terms like P700, P680, P870, Reaction centre, Light harvesting pigment molecule, Core molecule, Antennae molecules etc. The students tries to understand the concepts if they have doubts the students can clarify their doubts. Checking for understanding The teacher asks small questions to check the understanding of the students. Guided practice In guided practice the teacher explains the content once again to the students and clarifies their doubts. Teacher explains to the answers to the questions which were asked. In independent practice section divergent questions are asked to the students so that the skill of thinking will be increased. The questions are ; (1) Differentiate between reaction centre and light

107 Independent practice And Closure of the Lesson harvesting pigment molecule? (2) Why do photochemical reactions takes place only in the reaction centre? (3) What are the different types of light harvesting pigment molecule? (4) Differentiate between core molecule and antennae molecule?

108 LESSON TRANSCRIPT 8 NATURE OF LIGHT Author : School : Subject : Standard : Content Objective The student should know about the Nature of light. The solar spectrum is also explained to the students so that they should know the importance of visible spectrum in the solar spectrum. Stated objective Purpose or Goal of lesson (1) The pupil acquires the knowledge about the nature of light. (2) The pupil tries to understand about solar spectrum. (3) The pupil analyse the importance of visible spectrum in the process of photosynthesis. (4) The pupil organizes and classifies the new knowledge. (5) The pupil evaluates the function of solar spectrum. Anticipatory set or Introduction The teacher explains the Nature of light with the help of a diagrammatic sketch of the solar spectrum and the visible spectrum. Input or Procedure (1) Teacher presents the content with the help of a diagram. (2) For checking understanding small multiple choice questions are asked.

109 (3) In guided practice the content is explained once again for the students. (4) In independent practice small open ended questions are asked. Modelling The teacher explains the nature of light ie; the solar spectrum and the wave length for each light. Along with the explanation diagrammatical sketch is also shown for better understanding. The teacher introduces the new terms such as photosynthetic active radiation, photon and quantum. Checking for understanding For checking the understanding of the students the teacher asks multiple choice questions. Guided practice Independent practice and closure of the lesson After asking the questions the teacher would explain the content once again for the students for thorough understanding. Than the teacher explains the answers for all questions which was asked. In Independent practice the teacher ask small questions like: (1) Why solar spectrum is known as electromagnetic spectrum? (2) What is visible spectrum? (3) What are photosynthetically active radiations? (4) Define photon? (5) Define quantum?

110 LESSON PLAN 9 ABSORPTION SPECTRUM AND ACTION SPECTRUM Author : School : Subject : Standard : Content Objective Plus one students will have the knowledge about absorption and action spectrum. With the graphical representation of absorption and action spectrum the students build ups the knowledge in detail. Stated objective Purpose or Goal of lesson (1) The pupil acquires the knowledge of Absorption and Action spectrum. (2) The pupil understands the concept. (3) The pupil analyses the importance of Absorption and Action spectrum (4) The pupil organizes, evaluates and thus classifies the difference between Absorption and Action spectrum. (5) The pupil generalizes the importance of Absorption and Action spectrum in the process of Photosynthesis. Anticipatory set or Introduction Teacher explains the concept of Absorption and Action spectrum with the graphical representation. The students observation will be increased when they find out the difference between Absorption and Action spectrum.

111 Input or Procedure The lesson is prepared in different phases: 1. The concept is given in simple language for clear understanding graphical representation of Absorption and Action spectrum is shown. 2. Teacher guides the students to learn the lesson with divergent questions. 3. Teacher explains the questions through guided practice. 4. Students learn the lesson through thought provoking questions. Modelling Teacher first shows the graphical representation of absorption spectrum and motivates the students to define it. Like that Action spectrum is also taught. Checking for understanding The teacher after explaining the concept asks question to check the understanding of the students. Small multiple choice questions are asked so that if the students had understood the concept can answer easily. Guided Practice After asking questions if the students didn t answer the questions the teacher explains the answers with suitable examples. Here in guided practice the teacher explains the concept once again for the students.

112 Independent practice And Closure of the Lesson In Independent practice small open ended questions are asked. If the students have analyzed the concept the students will be able to answer the questions. The questions are: 1. Explain absorption spectrum? 2. What is Action spectrum? 3. How does the rate of photosynthesis measured? 4. Why does maximum rate of photosynthesis takes place in red light?

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