(iv) In what manner do the leaves 1 and 2 differ at the end of the starch test ? 14. Answer the following: (i) What is the aim of this experiment? Splitting of water molecules releases oxygen as a by-product. Answer: During the day, the chloroplast in the guard cells are able to carry on photosynthesis, so the osmotic pressure in the cell sap of the guard cells is high and water enters the guard cells which lead to an opening of the stomatal aperture. The main reaction which means the breaking up of water molecules through light. (ii) How many veins have been shown. (ii) The leaf portion which is not covered with black paper is the control as it receives sunlight. Question 21: On a bright sunny day water weeds growing in an aquarium were actively giving off bubbles of.gas. (iv). Boil the leaf in alcohol and wash in water. According to this law when a process is conditioned to its rapidity by a number of separate factors, the rate of process is limited by the pace of the lowest factor, i.e., the factor which is present in minimum amount. The portion covered with black paper remains colourless while rest of the leaf turn blue black. Form of energy which is converted into chemical energy during photosynthesis. (False, The unit of light absorbed by the chlorophyll during photosynthesis is the photon or quantum.) Maximise your exam preparation with Selina Solutions for ICSE Class 10 Biology Chapter 6 Photosynthesis. Carbon dioxide is reduced to carbohydrate in the dark reaction. 3. Question 5: ATP is needed for dark reaction. Question 3: Give some adaptations in a green leaf for photosynthesis. (ii) Take a potted plant and keep it for 2-3 days in dark to destarch its leaves. 2. 6. 2. (ii) List the events taking place in the photo-chemical phase of Photosynthesis. Question 4: What is the importance of photosynthesis in the life of the following : (i) Green plants (ii) Non-green plants (iii) Animals Answer: (i) Green plants are able to build up complex energy rich molecules of carbohydrates which are further used for different metabolic activities of cells. Source of oxygen given out in photosynthesis. Question 5: A leaf is a food factory. (iii) Select the correct leaf from the five available choices shown in the diagram as A, B, C, D and E. Rewrite the correct answer for the filling in the appropriate letter from the questions that follow: 1. Question 1: What are the basic requirements of photosynthesis ? A light induced reaction which leads to splitting of water is Photolysis of water. 9. Answer: Question 2: Draw a neat and well-labeled diagram of the apparatus you would set up to show that oxygen is given out during photosynthesis. The chlorophyll is found in the thylakoids and is the sight for the process of light reactions of photosynthesis to happen. (True) 12. Basic raw materials for photosynthesis (iii) CaO (limestone), potassium pyrogollate. Question 4: Chloroplasts are called energy converters. Intensity of light also determines the rate of photosynthesis. Photosynthesis is the process of plants and trees. Stomata – through which exchange of gases takes place. Thus they are dependent on photosynthesis. (True) 8. (iv) If ice cubes were added to the water, the rate of bubble formation would : (a) Remain the same. Solution: Biosynthetic phase of photosynthesis : • It occurs in the stroma of chloroplasts. Photosynthesis occurs only in plants. Chapter 6 Life Processes Class 10 Science Important Questions and Answers PDF will help you in scoring more marks. Answer: (i) 1. Photosynthesis is the process through which plants convert light energy from the sun to chemical energy. Chlorophyll 3. Answer: A destarched plant has no starch present in the leaves and a leaf remains yellowish-brown when tested with iodine during a starch test. Question: 1. Answer: (i) The object of this experiment is to show that CO2 is necessary for photosynthesis. 2. Increased concentration of carbon dioxide content enhances the rate of photosynthesis. Leaves are broad and flat to increase the surface area for photosynthesis. During this reaction, carbon dioxide and water are converted into glucose by chlorophyll in the presence of light energy. Green coloured plastids are chloroplasts rich in chlorophyll pigment. Answer: Question 3: Chloroplast and Chlorophyll. Phosphoglyceric acid is synthesised as the product. Justify your answer. The specific function of light energy in the process of photosynthesis is to: (a) Reduce.carbon dioxide (b) Synthesize glucose (c) Activate chlorophyll (d) Split water, 3. (ii) To remove all starch from the leaves of the plant. (b) Increases because more photosynthesis occurs. Question 6: Why green leaves are thin and broad ? (iii) (1) To kill the cells. (d) Decreases because water freezes. 2. H2 ———> H+ + OH–. 9. The Questions and Answers of Explain the process of photosynthesis? Water along with minerals is absorbed by roots and is carried to the sites of photosynthesis through xylem tissue. (iii) (a) I will select white light because photosynthesis is maximum in white light while it is minimum in green light as green light is reflected by green plants. If the answer is not available please wait for a while and a community member will probably answer this soon. NADP 10. (iv) Give an overall balanced chemical equation to represent the process named in (i) above. The main difference between chlorophyll ‘a’ and ‘b’ is: (a) Chlorophyll ‘a’ is a linear chain compound and ‘b’ is branched chain (b) Chlorophyll ‘a’ has no Mg ion in centre of molecule (c) In chlorophyll ‘a’ there is — CH3 group whereas in ‘b’ it is — CHO group (d) All of the above. • These reactions reduce the carbon dioxide into carbohydrates, making use of the ATP and NADPH 2 produced in the photochemical reactions. 10. Then in the early hours of the morning she covered one of the leaves with black paper in the centre only. (vi) The region of the leaf that was under the black strip turns yellowish-brown showing that no starch was made, while the rest of the leaf turns bluish-black showing the starch was made in the presence of light. Answer: Oxygen liberated during photosynthesis is a waste for the plant, so, it is released into air and is used by living organisms in respiration. (iv) Leaves are thin to allow rapid transport or diffusion of materials. (False, Photosynthesis occurs in all green plants.) What does Photosynthesis produce? (2) To destroy the chlorophyll. Question 22: What is meant by destarched plant ? 230-250 molecules of chlorophyll make one quantasome. Question 1: Draw a neat and well-labeled diagram of the Chloroplast. The thylakoids are arranged in stacks known as grana. No transpiration occurs during photosynthesis. Cuticle 2. She placed the potted plant in the sunlight for a few hours, and then tested the leaf which was covered with black paper for starch. Too much light destroys chlorophyll. The process of photosynthesis requires solar energy, water and carbon dioxide. (True) 15. Question 16: Explain why transpiration and photosynthesis are interlinked during the day. Insert one of its leaves in a conical flask, which contains potassium hydroxide. Photosynthesis occurs in all the cells of a plant. Answer: Blackman (1905) established the law of limiting factor in connection with photo-synthesis. The thylakoids are arranged in stacks known as grana. Photosynthesis is the process of converting the energy in which solar energy is converted into the … (iv) Light supplies eiergy in the form of photons to split water during tight reaction. (i) From the graph it seems likely that the rate of bubbling per minute at 50 cm., would have been : (a) 2-0 (b) 2-5 (c) 3-0 (d) 3-5 (e) 4-0, (ii) The gas produced by the plant during the experiment was : (a) Air (b) Oxygen (c) Carbon dioxide (d) Nitrogen (e) Hydrogen, (iii) The gas collected comes due to the breakdown of: (a) Glucose (b) Starch (c) Water (d) Air (e) ATP. Xylem 5. It is a process of splitting of water molecule into 2H+ + 4e- + 1/2 O2 in the presence of sunlight by activated photosynthetic pigments. Thylakoids. Question 7: A well watered healthy potted plant with variegated leaves was kept in darkness for about 24 hours. Name the experiment to demonstrate the importance of light for photosynthesis. (Chlorophyll), 1. 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