Cbse 10th Std Biology | Life Proccesses | Part 3

Ajouté : 2026-06-03

[00:00:05]jungle.

[00:00:08]Hello guys, welcome back to my channel.

[00:00:11]In this class, we will learn CBC 10 standard biology. Lesson name is life process. In the past classes, we learned about what do you mean by life process?

[00:00:22]Life process are the process or processes or the movements done by our body to sustain our life in this world.

[00:00:31]Then we learned the different type of life processes. Then we learned the subtypes of there too. So in the last class we stopped while learning the site of photosynthesis. We learned that site of photosynthesis is chloroplast in which chloro field is present the green pigment which helps in the photosis so that it would trap the sunlight. So how does it obtain the gases required?

[00:01:06]So in this class we are going to learn about stomata. Stomata are the tiny pores present on the leaves. So there are some tiny pores present in a leaf which helps in some functions that is exchange of gases. It helps in exchange of gases and transpiration.

[00:01:30]So what do you mean by this exchange of gases? What is happening in stomata during this exchange of gases? So exchange of gases means carbon dioxide enters the leaf through stomata for photosynthesis. So one of the most important thing required for the photosynthesis is carbon dioxide. So how does the plants obtain the carbon dioxide which is present outside the plants or the atmosphere?

[00:02:00]It needs some opening to enter. So stomata is the pore opening which allows the carbon dioxide to enter so that the photosynthesis will take place in the plant and oxygen is released out through the stomach after the happening of the photosynthesis.

[00:02:22]The outcome or the final product is oxygen. So that should be released out to air. It can't store so much oxygen.

[00:02:31]So it will just release it out to the air. So stomata is a opening in the green plants which helps in the exchange of gases. That means taking in of carbon dioxide and letting out the oxygen. Then comes transpiration.

[00:02:51]Transpiration is a process extra water is lost from the plant in the form of water vapor through stomata. So the transpiration is the process in which the extra water present inside the plants. So there is a limit for storage of water in the plants. If the excess water is present in the plants, this is a method of throwing out the extra water in the form of plant in the form of water vapors. So the extra water is expelled out of the plants in the form of water vapors. So how does it happens? When the stomata opens for exchange of gases due to the sunlight or the heat, the water gets vaporized and just go out. So it's a method of getting out of the excess water present inside the plants. So what is the opening? The opening and closing of the pore is controlled by the kidney bean shaped cell called it guard cell.

[00:04:07]So here we understand new term that is guard cell. It's the cell which is shaped like kidney. We can see here this is known as guard cell. These two shells is known as guard cell which controls the opening and closing of the stomata.

[00:04:32]Then here comes the stomatal group and this small green pigment is known as chloroplast or the site of photosynthesis.

[00:04:43]So the opening and closing of the pore is controlled by kidney bean shaped cells known as guard cell. So this controls the opening and the closing of stomatas present in the green plants. So if the opening while the opening happens the carbon dioxide is enter and while the carbon dioxide enter the due to the sunlight heat the water gets vaporized since it's in the normal places the sunlight is not that hot that can vaporize whole water present in the plant but think about the desert plants.

[00:05:26]So if the desert plants how does it get carbon dioxide if it opens for the carbon dioxide the whole water in the plant will get EXPELLED OR VAPORIZED if it just opens that much or sunlight produces that much heat that it can vaporize that amount of water from the plants present in the desert. So here the desert plants will have a special function that it will take in the carbon dioxide required at the night. So at the night sun set down and the uh desert plants will open their stomat up so that it can store as much as carbon dioxide as possible and after that they will just use it for morning the chlorophyll and with the chlorophyll it traps the sunlight. So the trapid carbon dioxide at night will be used for the same photosynthesis when the morning sunlight come. Since it can't do the process of photosynthesis without the sunlight it will wait till the morning and when the time comes they will just do the photosynthesis and store the outcome again and release it out at night. So this is a special function of the desert plants. They take exchange of gases is happening at the night time and the process of the photosynthesis is happening at the presence of sunlight.

[00:07:05]That means when the sunlight will come they will do the process of photosynthesis. Without the sunlight we can't do the photosynthesis. And here we understand one more term that is without the carbon dioxide also we can't do the process of photosynthesis since these both are the most important and essential key components required for the process of photosynthesis.

[00:07:33]Now we have learned what are the functions of this tomato. This tomato will open and close. We know that. But how does this process will happen? How does the stomata knows that the water is excessive in the plants? How does it get the signals? So we learn that guard cell is the one of the important bean shaped cell in the stomata. So the same guard cells helps in this detection of the excessive water. When the water is excessive and reaches the stomata, the guard cells swells. When it swells, it will open up so that the evaporation or vaporation could takes place. Then when the water is not excessive after some time of opening of the guard cell, the water will be vaporized. After that the excessive water in the plants will be in the atmosphere. So the water will be drowned and removed from the guard cell. So since the water is not present in the guard cell, the guard cell slowly comes to normal and closes.

[00:08:55]So when it switch it will open. So this is how the opening and closing of the guard cell take place. So there is one experiment mentioned in our NCERT that is the experiment of K.

[00:09:14]The experiment which proves us that carbon dioxide is essential for photosynthesis.

[00:09:21]So let's talk about this experiment. So first we have to do two similar plants.

[00:09:27]were taken for fair competition. So you have to take two similar plants for this competition or we can say comparison.

[00:09:38]Both plants were kept in the dark for 3 days to remove stored starch. So starch is the food stored after the photosynthesis.

[00:09:48]So when it kept in the dark for 3 days that means no sunlight is coming that means no photosynthesis is happening here. Since no photosynthesis happening new starch is not forward. So to remove the store starch that means to get a perfect result you should remove the old stock of starch present in the photos in the all the plants. So 3 days it will have excessive or the storage of the starch. So after that the storage starch will be removed by the daily usage. If there is no sunlight there is no new starch is formed. Since no new starch is formed, that means old stock will be emptied as usual. And it's obvious if you don't buy new things and you will be using your old foods or something but it will be emptied because you are not buying any new. If you have a income then only you can spend as you want but you don't have a income but your expense or is too much that you can't handle that means it will become zero at last you have 1,000 rupees so then you are getting daily 100 that means you can spend daily 100 because that won't won't interrupt your income because you're getting the income and your expense will be zero unless it won't be zero unless you don't forget to get the 100. So you are not getting the 100 rupees anymore but you are still spending that 100 rupees. That means eventually it will become zero. Same way the stored starch is emptied by keeping in the dark light for 3 days. Then each plants was separated to create new two different starch. So each plant kept separate so that it can create new starch so that the plant don't die. K was kept with one plant because it absorbs carbon dioxide. So Ka is a type of a chemical we can say which will absorb all the star all the carbon dioxide present in the atmosphere. So you are taking a plant and keeping the chaot near it that means carbon dioxide is no more entering the pore and the plant doesn't get carbon dioxide because ko is placed there. So if there is chaos present in the atmosphere then the carbon dioxide will be removed from the surrounding. So both plants were covered with the bell jars to make closed setup.

[00:12:51]That means if you put a bell jar the around it surrounding more carbon dioxide will not enter so that it can control the KO. That means the KO is dominating here and all the carbon dioxide is sucked up and there is no carbon dioxide in the gel bar. So we can see the example like this is the gel bar. This is the plane area. Here the plant is kept and here KO H is placed.

[00:13:28]So there is no more new carbon dioxide is entering. So here carbon dioxide is fully empty. That means carbon dioxide is not present.

[00:13:41]Wastel was used to make the setup of air. So wastel was used it so that the air tight setup is made. Both plant were kept in sunlight so photosynthesis could occur. We know without the sunlight the photosynthesis will not happen. It's kept in bark that means sunlight can still enter it. So that means that photosynthesis should happen. The photosynthesis should happen. There are two A and B. So in the second one the photosynthesis will happen. Why? Because carbon dioxide is not present in what leaves were tested with iodine to check the starch formation. So after some days or some time we will just check which will have the starch in it. We know the iodine test. So they does this test. So according to the result leaf with the ko did not turn blue black. So if the thing doesn't turn blue black after applying the iodine that means that there is zero starch present in it. If the starch is present in the item or the leaf then the it will turn into blue black color. So since the leaf with K did not turn blue back blue black then it means no starch is forward. But on the opposite side the leaf with without the chaos turned blue back blue black because the carbon dioxide is present in it. And here at the A case that doesn't have starch because the carbon dioxide is not there.

[00:15:33]Hereby we understand that carbon dioxide is one of the important thing required for the photosynthesis. If the carbon dioxide is not present in the plant or it doesn't get carbon dioxide somehow then the photosynthesis won't happen in the plants. So the conclusion is CO2 is necessary for photosynthesis.

[00:15:58]So for this conclusion you have to write these details. First you take two plants. Both plants will kept in sun dark because to remove the starch present in it. Then you will place in one k and in another you don't place anything. Then you put the belcha and use vaseline to tight the air supply.

[00:16:24]Then both plants is kept in sunlight because without the sunlight the photosynthesis won't happen even the carbon dioxide is present in the plants.

[00:16:33]So leaves were tested with iodine after that if the starch is present it will turn into blue black color and if the starch is not present then it will be normal. So in the case A it did not turn blue black because CO2 was absent in that case and case B leaf without KO turned blue black because CO2 was present in that. So hereby WE UNDERSTAND WITHOUT THE CARBON dioxide and the sunlight present the photosynthesis won't happen in the plants.

[00:17:12]So hereby I conclude this class. I I think you understood what I thought about this experiment and the stomat opening and closing and the functions of the stomata taught in this class. In the upcoming classes we will learn more about this chapter life process. So if you like my video like share and subscribe to my channel. Bye.