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Updated May 1, 2026
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Energy Flow in Ecosystems - Study Notes
Chloé Merson
@chlomerson_7
1 / 3
Energy Transfer in Food Chains
Food chains show how energy moves through an ecosystem across different trophic levels. They typically include producers (like grass), primary consumers (like zebras), secondary consumers (like lions), and sometimes tertiary consumers. The original energy comes from the sun and enters the ecosystem through plants during photosynthesis.
Only about 10% of energy is passed from one trophic level to the next. This means a whopping 90% of energy is lost at each transfer! This energy disappears as heat, gets used for movement, or remains in undigested material like bones and feces.
The small amount of energy that does transfer (that 10%) is used by organisms for important processes like growth, movement, and heat production. This is why there are fewer organisms at higher trophic levels - there simply isn't enough energy to support large populations.
Remember this! The energy passed between organisms is chemical energy used for growth, which is why biomass (the amount of living material) decreases as you move up the food chain.
Pyramids of Numbers and Decomposers
Decomposers play a crucial role in ecosystems by breaking down dead organisms and waste materials. Unlike other consumers, they can be found at all levels of food chains since they feed on the remains from every trophic level.
A pyramid of numbers shows the population size of each species at different trophic levels. While these pyramids often look like actual pyramids (with many producers at the bottom and fewer consumers at the top), some situations create unusual shapes.
For example, in a food chain with an oak tree, caterpillars, shrews, and owls, the pyramid might look inverted at the bottom. This happens because a single large producer (like one oak tree) can support thousands of primary consumers (caterpillars).
Think about it: Pyramids of numbers don't account for organism size, which can sometimes make them misleading. A single large tree provides more energy than several small plants, even though it counts as just "one" in the pyramid.
Pyramid of Energy
Unlike pyramids of numbers, pyramids of energy always form a true pyramid shape. These diagrams show the total energy contained within each population at every trophic level, typically measured in kilojoules (kJ) or kilocalories (kcal).
The pyramid shape is consistent because energy always follows the same pattern in ecosystems: maximum energy at the producer level (bottom) and progressively less energy at each higher level. This reflects the fundamental principle that energy is lost at each transfer.
Energy pyramids give us the most accurate picture of ecosystem structure since they measure what truly limits population sizes - available energy. Even when a single large producer supports many consumers, the energy pyramid still shows the expected decrease at higher levels.
Important concept: Energy pyramids never invert because they represent the fundamental law of energy transfer in ecosystems - you can't have more energy at a higher level than the level below it!
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This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
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Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
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Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
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This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
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The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
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In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
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very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
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I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
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Energy Flow in Ecosystems - Study Notes
Chloé Merson
@chlomerson_7
Energy flow through ecosystems is a fascinating process that powers all life on Earth. Starting with the sun, energy travels through food chains, being transferred and transformed at each step, with significant portions being lost along the way.
Energy Transfer in Food Chains
Food chains show how energy moves through an ecosystem across different trophic levels. They typically include producers (like grass), primary consumers (like zebras), secondary consumers (like lions), and sometimes tertiary consumers. The original energy comes from the sun and enters the ecosystem through plants during photosynthesis.
Only about 10% of energy is passed from one trophic level to the next. This means a whopping 90% of energy is lost at each transfer! This energy disappears as heat, gets used for movement, or remains in undigested material like bones and feces.
The small amount of energy that does transfer (that 10%) is used by organisms for important processes like growth, movement, and heat production. This is why there are fewer organisms at higher trophic levels - there simply isn't enough energy to support large populations.
Remember this! The energy passed between organisms is chemical energy used for growth, which is why biomass (the amount of living material) decreases as you move up the food chain.
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Pyramids of Numbers and Decomposers
Decomposers play a crucial role in ecosystems by breaking down dead organisms and waste materials. Unlike other consumers, they can be found at all levels of food chains since they feed on the remains from every trophic level.
A pyramid of numbers shows the population size of each species at different trophic levels. While these pyramids often look like actual pyramids (with many producers at the bottom and fewer consumers at the top), some situations create unusual shapes.
For example, in a food chain with an oak tree, caterpillars, shrews, and owls, the pyramid might look inverted at the bottom. This happens because a single large producer (like one oak tree) can support thousands of primary consumers (caterpillars).
Think about it: Pyramids of numbers don't account for organism size, which can sometimes make them misleading. A single large tree provides more energy than several small plants, even though it counts as just "one" in the pyramid.
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Pyramid of Energy
Unlike pyramids of numbers, pyramids of energy always form a true pyramid shape. These diagrams show the total energy contained within each population at every trophic level, typically measured in kilojoules (kJ) or kilocalories (kcal).
The pyramid shape is consistent because energy always follows the same pattern in ecosystems: maximum energy at the producer level (bottom) and progressively less energy at each higher level. This reflects the fundamental principle that energy is lost at each transfer.
Energy pyramids give us the most accurate picture of ecosystem structure since they measure what truly limits population sizes - available energy. Even when a single large producer supports many consumers, the energy pyramid still shows the expected decrease at higher levels.
Important concept: Energy pyramids never invert because they represent the fundamental law of energy transfer in ecosystems - you can't have more energy at a higher level than the level below it!
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Stefan S
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This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
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Anna
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Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
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This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user