hi everyone welcome back to online classroom jay kudio in this video we are going to look at the first topic of chapter 2 that is the energy flow in an ecosystem do you know what is the source of energy in all ecosystems it is actually the sun why because the green plants will convert the light energy from the sun into chemical energy in another word food through photosynthesis and the chemical energy will then be transferred to primary consumers followed by secondary and tertiary consumers in the food chain and food web wait a minute what is all this consumers food chain and food web don't worry dekutio will explain one by one okay be patient while in ecosystem all the organisms can be classified into three main group that is the producer consumer and also the composer let's look at them one by one the producer are the ones that produces its own food through photosynthesis so the producers are actually green plants how about the consumer consumers are the ones that eat another organism okay so before we look at different consumer we have to know that consumer can be classified into three different types primary consumer secondary consumer and tertiary consumer there's actually higher level up after tertiary consumer but for now you will get the concept as you understand what is primary secondary and tertiary consumer before we look at that let's have a little bit of revision her before are the animals that eat only plants whereas carnivores are organism that eats animal and omnivore they eat both okay so what is a primary consumer primary consumer is producers and they are normally herbivores and also omnivores secondary consumer is the next level so they eat primary consumer okay and they are normally omnivore and carnivore and tertiary consumer as you can guess they eat secondary consumer and they are mostly carnivore okay how about decomposer decomposer are the ones that actually breaks down dead animals and plants into simpler materials or nutrients and this interaction is actually called saprophytism okay a good example of the composer will be the mushroom another example will be bacteria mushroom and bacterias are actually decomposer so now that we have learned the technical part we have learned all these terms let's look at an illustration of all of this so here's a green plan as we have learned a green clan is a producer because they can make their own food from photosynthesis okay a green plant say is eaten by a caterpillar and this caterpillar is a consumer and because the caterpillar eat the producer it is a primary consumer and the caterpillar will be eaten by a bird and a bird is actually a secondary consumer because the bird eats the primary consumer and let's say this bird is eaten by a fox and now this fox is categorized as tertiary consumer the caterpillar the bird and the fox that eat another organism okay they do not they do not produce their own food they cannot go through photosynthesis so they are consumer they need to eat another living thing whereas for producer they don't need other living thing they can make their own food that is why they are called the producer and when all those living things die their bodies their dead bodies will be decomposed by who by the decomposer some example will be the mushroom or the bacteria so can you understand better now what is the producer consumer and the composer and also consumer they have they have different level the primary the secondary and the tertiary it should be easier to understand now right next let's look at food chain what is food chain food chain is actually used to show feeding relationships between organism between the living things i'll show you an example of food chain cabbage is eaten by snail and snail is eaten by bird and a bird is eaten by a fox so this is a food chain in this food chain it shows you the feeding relationship and this arrow actually means energy flow so the energy in the cabbage will flow to the snail because the snail eat the cabbage and get some energy so the energy flow from cabbage to snail and the energy from the snail will flow to the bird and the bird the energy will flow to the fox because fox eats bird okay so the arrow means energy flow now can you identify which one is the producer and consumer the cabbage is the producer because the cabbage is the green plant and snail bird and forks are all consumer where the snail is the primary consumer the bird is the secondary and the fox is a tertiary consumer it should be really easy right okay how about a food web a food web actually is formed when we combine a few other food chains i'll show you an example this is the food web okay so cabbage is eaten by three other different living things that are the caterpillar snail and grasshopper and all these three living things the caterpillar snail and grasshoppers are eaten by bird and grasshopper is also eaten by a frog the bird and the frog is then eaten are then eaten by a snake and one and the same as the food chain the arrows here mean energy flow so just like i said earlier on food web is formed by the combination of different food chain so from this food web can you find the food chain that formed them let's look at them one by one first will be cabbage caterpillar bird and snake and then cabbage snail bird and snake another food chain will be cabbage grasshopper bird and snake one more cabbage grasshopper frog and snake so if you combine all these four food chains you get a food web here okay so just like dekutio has mentioned earlier the arrow here means the energy flow that's all the energy in cabbage go to the snail when the snail eat the cabbage or when the grasshopper eat the cabbage does all the energy in the cabbage go to the grasshopper actually the answer is no okay the energy is transferred from one organism to another organism but it is not transfer as a whole meaning it it it doesn't go completely to the next organism why because there will be some energy loss okay the energy in cabbage will transfer to grasshopper in the meantime during the process some energy is lost then when the energy in grasshopper is transferred to say the frog the fruit eat the grasshopper there will be some energy loss as well and some energy transfer to the frog where does this energy go to well that can be lost in a different of ways first will be movement most of the organism here most of the living things here they move as you move you use energy when you use up the energy the energy is lost respiration all living things go through respiration and it can be lost also as heat energy or chemical energy through undigested food or faces meaning when they poop they lost energy so that's how there are some energy lost as the energy flow through the food web or the food chain okay so that's all from jay gutier in this video i shall see you in the next video bye if you have learned something new from this video don't forget to like and subscribe