Biology
Chemistry
AP Chemistry
English
AP English Literature
549
•
Nov 26, 2025
•
Vivian Nguyen
@ivianguyen_bnxh
Ecosystems are complex networks of living organisms interacting with their... Show more
Ever wonder why certain animals live together or why some environments have more plants than others? It all comes down to relationships! An ecosystem is a community where living organisms interact with nonliving components as a system.
Living (biotic) components include producers like plants, and consumers like herbivores, carnivores, and omnivores. Nonliving (abiotic) factors include sunlight, temperature, precipitation, and soil pH. These relationships can be predator-prey (where predator populations follow prey populations over time) or symbiotic (living together). Symbiotic relationships come in three types: mutualism (both benefit), commensalism (one benefits, one unaffected), and parasitism (one benefits, one harmed).
When resources are limited, competition occurs either between different species (interspecific) or within the same species (intraspecific). To reduce competition, species develop resource partitioning - using the same resources in different ways.
Ecosystems are organized from small to large: organism → population → community → ecosystem → biome → biosphere. Terrestrial biomes are characterized by temperature, precipitation, and latitude. Generally, hotter and more humid regions support greater biodiversity and primary productivity.
Remember this! Climate graphs are important tools that show both temperature and precipitation patterns in different biomes - they help explain why certain plants and animals live where they do.
Water covers most of our planet, creating diverse habitats for life! Aquatic biomes are divided into freshwater (wetlands, streams, rivers, ponds, lakes) and marine (intertidal zones, estuaries, coral reefs, open ocean). Unlike terrestrial biomes that are defined by temperature and precipitation, aquatic biomes are characterized by depth, oxygen levels, light penetration, and nutrient availability.
Wetlands include marshes , swamps (wooded areas), and bogs (acidic areas with sphagnum moss). In oceans, the photic zone receives sunlight allowing photosynthesis, while the aphotic zone is too deep for light to penetrate. Coral reefs and estuaries have high primary productivity and biodiversity because of their nutrient-rich waters.
The carbon cycle moves carbon atoms between different reservoirs on Earth. This biogeochemical cycle is self-regulating but can be disrupted by human activity. Carbon moves through fast cycles (biological processes like photosynthesis and respiration) and slow cycles (geological processes like sedimentation and fossil fuel formation).
During photosynthesis, producers convert carbon dioxide and water to glucose and oxygen. Through respiration, organisms break down glucose to release energy, producing carbon dioxide and water. Decomposition returns carbon to the atmosphere through respiration and to soil through breakdown of organic matter.
Fun fact: The ocean sediment and fossil fuels are Earth's largest carbon reservoirs, storing carbon for millions of years until released by combustion or weathering!
Just like we need nutrients to grow, ecosystems need certain elements to thrive! The nitrogen cycle is crucial because nitrogen is a major component of amino acids (building blocks of proteins) and nucleic acids (building blocks of DNA). Despite making up 78% of our atmosphere, most organisms can't use nitrogen directly from the air.
The cycle involves several key processes: nitrogen fixation (converting N₂ to usable forms via lightning or microbes), ammonification (converting organic nitrogen to ammonia), nitrification (converting ammonia to nitrite then nitrate), assimilation (plants absorbing nitrogen compounds), and denitrification (returning nitrogen to the atmosphere).
The phosphorus cycle differs from other cycles because it's incredibly slow and primarily geological - almost none occurs in the atmosphere. Phosphorus is weathered from rocks, moves through soil and water, and eventually forms sediments again. This limited availability makes phosphorus a limiting factor for ecosystem productivity.
The water cycle is essential to all life and driven by solar energy. Water moves between states (solid, liquid, gas) through processes like evaporation, condensation, precipitation, runoff, and groundwater flow. The ocean serves as the largest water reservoir on Earth.
Important connection: Both nitrogen and phosphorus are common in fertilizers because they enhance plant growth. However, when these nutrients run off into waterways, they can cause harmful algal blooms!
Have you ever wondered how energy moves through an ecosystem? It all starts with primary productivity - the rate at which solar energy is converted into organic compounds through photosynthesis. This forms the foundation of nearly all ecosystems!
We measure productivity in two ways: Gross Primary Productivity (GPP) is the total rate of photosynthesis, while Net Primary Productivity (NPP) is what remains after the producers use some energy for themselves . NPP represents the energy available for consumers in the ecosystem.
Energy transfers through trophic levels - from producers to primary consumers to secondary consumers and beyond. According to the 10% rule, only about 10% of energy transfers from one level to the next. The rest is lost as heat or used for life processes, following the laws of thermodynamics.
A food chain shows a single pathway of energy through an ecosystem, while a food web shows interconnected chains that more accurately represent the complexity of real ecosystems. These models help us understand how energy flows and how disruptions to one species can affect many others.
Why this matters: The 10% energy transfer rule explains why there are always fewer carnivores than herbivores in a balanced ecosystem - and why eating lower on the food chain is more energy-efficient!
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
Google Play
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. 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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. 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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Vivian Nguyen
@ivianguyen_bnxh
Ecosystems are complex networks of living organisms interacting with their environment. This unit explores how different species interact, how energy flows through ecosystems, and the cycling of essential elements that sustain life on Earth. Understanding these connections helps us see... Show more
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Ever wonder why certain animals live together or why some environments have more plants than others? It all comes down to relationships! An ecosystem is a community where living organisms interact with nonliving components as a system.
Living (biotic) components include producers like plants, and consumers like herbivores, carnivores, and omnivores. Nonliving (abiotic) factors include sunlight, temperature, precipitation, and soil pH. These relationships can be predator-prey (where predator populations follow prey populations over time) or symbiotic (living together). Symbiotic relationships come in three types: mutualism (both benefit), commensalism (one benefits, one unaffected), and parasitism (one benefits, one harmed).
When resources are limited, competition occurs either between different species (interspecific) or within the same species (intraspecific). To reduce competition, species develop resource partitioning - using the same resources in different ways.
Ecosystems are organized from small to large: organism → population → community → ecosystem → biome → biosphere. Terrestrial biomes are characterized by temperature, precipitation, and latitude. Generally, hotter and more humid regions support greater biodiversity and primary productivity.
Remember this! Climate graphs are important tools that show both temperature and precipitation patterns in different biomes - they help explain why certain plants and animals live where they do.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Water covers most of our planet, creating diverse habitats for life! Aquatic biomes are divided into freshwater (wetlands, streams, rivers, ponds, lakes) and marine (intertidal zones, estuaries, coral reefs, open ocean). Unlike terrestrial biomes that are defined by temperature and precipitation, aquatic biomes are characterized by depth, oxygen levels, light penetration, and nutrient availability.
Wetlands include marshes , swamps (wooded areas), and bogs (acidic areas with sphagnum moss). In oceans, the photic zone receives sunlight allowing photosynthesis, while the aphotic zone is too deep for light to penetrate. Coral reefs and estuaries have high primary productivity and biodiversity because of their nutrient-rich waters.
The carbon cycle moves carbon atoms between different reservoirs on Earth. This biogeochemical cycle is self-regulating but can be disrupted by human activity. Carbon moves through fast cycles (biological processes like photosynthesis and respiration) and slow cycles (geological processes like sedimentation and fossil fuel formation).
During photosynthesis, producers convert carbon dioxide and water to glucose and oxygen. Through respiration, organisms break down glucose to release energy, producing carbon dioxide and water. Decomposition returns carbon to the atmosphere through respiration and to soil through breakdown of organic matter.
Fun fact: The ocean sediment and fossil fuels are Earth's largest carbon reservoirs, storing carbon for millions of years until released by combustion or weathering!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Just like we need nutrients to grow, ecosystems need certain elements to thrive! The nitrogen cycle is crucial because nitrogen is a major component of amino acids (building blocks of proteins) and nucleic acids (building blocks of DNA). Despite making up 78% of our atmosphere, most organisms can't use nitrogen directly from the air.
The cycle involves several key processes: nitrogen fixation (converting N₂ to usable forms via lightning or microbes), ammonification (converting organic nitrogen to ammonia), nitrification (converting ammonia to nitrite then nitrate), assimilation (plants absorbing nitrogen compounds), and denitrification (returning nitrogen to the atmosphere).
The phosphorus cycle differs from other cycles because it's incredibly slow and primarily geological - almost none occurs in the atmosphere. Phosphorus is weathered from rocks, moves through soil and water, and eventually forms sediments again. This limited availability makes phosphorus a limiting factor for ecosystem productivity.
The water cycle is essential to all life and driven by solar energy. Water moves between states (solid, liquid, gas) through processes like evaporation, condensation, precipitation, runoff, and groundwater flow. The ocean serves as the largest water reservoir on Earth.
Important connection: Both nitrogen and phosphorus are common in fertilizers because they enhance plant growth. However, when these nutrients run off into waterways, they can cause harmful algal blooms!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Have you ever wondered how energy moves through an ecosystem? It all starts with primary productivity - the rate at which solar energy is converted into organic compounds through photosynthesis. This forms the foundation of nearly all ecosystems!
We measure productivity in two ways: Gross Primary Productivity (GPP) is the total rate of photosynthesis, while Net Primary Productivity (NPP) is what remains after the producers use some energy for themselves . NPP represents the energy available for consumers in the ecosystem.
Energy transfers through trophic levels - from producers to primary consumers to secondary consumers and beyond. According to the 10% rule, only about 10% of energy transfers from one level to the next. The rest is lost as heat or used for life processes, following the laws of thermodynamics.
A food chain shows a single pathway of energy through an ecosystem, while a food web shows interconnected chains that more accurately represent the complexity of real ecosystems. These models help us understand how energy flows and how disruptions to one species can affect many others.
Why this matters: The 10% energy transfer rule explains why there are always fewer carnivores than herbivores in a balanced ecosystem - and why eating lower on the food chain is more energy-efficient!
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. 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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. 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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
