in this video we are going to learn some experiments on respiration in plants so this is the first experiment and its aim is to show that oxygen is used up in respiration in the figure you can see an apparatus is arranged where you can see two flasks that is flask a and flask B flask a contain germinating bean seeds where as flux B contain dead boiled seeds both the flasks contain wet cotton wool to provide water to both the sample just because flux B contains dead bean seeds it is provided with antiseptic that is carbolic acid otherwise the bacteria will grow respire and will release carbon dioxide and will hamper the experiment now observe carefully both the flux containing small tube which consists of soda lime so what is soda lime it is a mixture of sodium hydroxide and slake lime the function of soda lime is to absorb any carbon dioxide released by the seeds now this setup is kept for few days so after a few days what we will observe that there is a rise in water level through delivery tube in flask a next burning paper is introduced in each flask after removing their corks we will observe that the flame is immediately put off in flask a but it continues for a short while in flask B so this proves that oxygen was absent in flask a thereby showing that the oxygen is used up by the germinating seeds and the volume of oxygen is used was indicated by the rise of water level in the delivery tube now there are two simple questions for you so first one is why there is a slight increase in the level of water in the delivery tube or flask B so there are two answers of this question number one is capillary action so what is capillary action see if you open the bottle of a coke and put a straw in it you will see without your sipping some amount of water will enter into the straw so this is called capillary action next me some amount of carbon dioxide gas is trapped in flask B as a result of which soda lime absorbed that is a carbon dioxide and created partial vacuum over there and this vacuum helped in rising the water level in the delivery tube connected with flask B the next question is which of the two flasks that is a or B is a control remember that any experiment consists of two setups an experimental setup and a control setup so the setup in which the conditioned understudies missing is called the control so here the flux P is the control so from this experiment we learn that oxygen is essential for the plant for respiration our next experiment is to prove that carbon dioxide is produced during respiration in germinating seeds so again here given two flasks that is flask a and flask B at the bottom of each flask is place of wet cotton wool short seeds such as being or pea are placed in flask a and an equal number of boiled dead seeds are placed in flask B here also little antiseptic such as carbolic acid is added to flux B to prevent bacterial growth on dead seeds which would otherwise respire and release carbon dioxide both the flasks are cork and kept in similar condition of light and temperature here after few days the season flask cave will be found to have clearly germinated seeds whereas in flask be showing no sign of germination as because they are dead the gases in each flask are then tested by removing the and tilting the flask over a test tube containing lime water and then shaking up the test tube the expected gas that is carbon dioxide being heavier than the air would flow down into the test tube the gas from flask a would turn the line water milky showing the presence of carbon dioxide in it while the gas in flask B will show no effect so what we can conclude from this that the germinating that is respiring seeds give out carbon dioxide there is an alternative method for the same experiment in this experiment the air drawn in conical flask a is cleared of any co2 present in it the clear lime water in flask B confirms that the air entering flower C is co2 free the lime water in flowers T turning milky which proves that the source of co2 was only the germinating seeds the next experiment was conducted to prove that carbon dioxide is produced by green plants during respiration here the apparatus has been set up using a small potted plant such as geranium the Belcher in the middle should be placed on a glass sheet and its rim as well as all other connection should be Westland to make them airtight it observe the flask a which is connected with a pump in which the outside air is drawn into the apparatus this air passes through the sewer line which absorb any carbon dioxide present in the incoming air lime water in flask a through which this air is passes will not turn milky as the air leaves the Belcher and passes through another sample of lime water that is flask B the carbon dioxide present in it would turn the lime water milky but before conducting this experiment we need to take some precautions number one is this experiment should be carried out in the dark or the Belcher is completely covered by a piece of black cloth to prevent photosynthesis so that the carbon dioxide liberated in respiration is not used up in the synthesis of starch here we would be performing another experiment which will show that heat is evolved during respiration here two thermos flasks have been taken flasks a contain germinating seeds whereas flus be contained dead seeds with antiseptic to prevent bacterial decay both the flasks are inserted with a thermometer and their mouth has been plugged with cotton wool after a few hours the thermometer in flask I will show a higher reading thus indicating that the germinating seeds give out heat whereas the flask B is not showing any rise in temperature thus from this experiment we concluded that respiring seeds produces Heat now coming to the last experiment where we would demonstrate that respiration can takes place in absence of oxygen that is the experiment on is to demonstrate the anaerobic respiration so first take a 210 soaked and peeled off piece and push them into the mouth of a test tube filled with mercury and inverted in a beaker of mercury the sieves will flow to the top and will be completely surrounded by mercury after about two days the level of mercury in the test tube will fall and the liberated gas will be found to be carbon dioxide carbon dioxide can be tested how by introducing a stick of potassium hydroxide into the test tube which will float up through mic mercury and on coming in contact with the gas will absorb the carbon dioxide and the level of mercury will again rise a similar control experiment could be set up in which the seeds may be kept after killing them by heating and sterilizing them with some antiseptic no gas will be liberated in the control room now the question is why we are peeling of the seed coat of the germinating seed before introducing them into the test tube we are doing so to Hassen the outward diffusion of carbon dioxide gas