Subjects
Biology
Chemistry
AP Chemistry
English
AP English Literature
Biology
Dec 11, 2025
72
6 pages
Billie Bowen @billiebowen_jqah
Atoms, cells, and microscopes might seem complicated, but they're actually the building blocks that make up everything around... Show more
Ever wondered what makes gold different from carbon? It's all about elements – substances made up of atoms that have the same number of protons in their nucleus. Think of elements as the pure ingredients of everything in the universe.
The atomic number tells you exactly what element you're dealing with because it counts the protons. If you change the number of protons, you get a completely different element – it's like nature's ID card system.
Isotopes are basically twins with different weights. Carbon-12 and carbon-13 are both carbon (same number of protons), but carbon-13 has an extra neutron making it slightly heavier. Scientists use these to calculate relative atomic mass, which is just the average weight considering all the different isotopes.
Quick Tip Remember that protons determine the element type – everything else can vary!
Atoms are incredibly tiny – about 0.1 nanometers across – but they're perfectly organised little worlds. Picture a football stadium where the nucleus (containing protons and neutrons) is like a marble in the centre, whilst electrons zoom around the edges.
The nucleus packs almost all the atom's weight into a space 10,000 times smaller than the whole atom. Protons are heavy and positive, neutrons are heavy but neutral, and electrons are tiny with a negative charge.
Here's the clever bit atoms are normally neutral because they have equal numbers of protons and electrons. When atoms become ions (charged particles), they've either gained or lost electrons. Add electrons for negative ions, lose them for positive ones.
Memory Trick Electrons are on the outside, so they're the ones that can escape or join – protons stay put in the nucleus!
Stem cells are like biological shape-shifters – they can transform into any type of cell your body needs. Imagine having a bunch of blank cells that could become brain cells, muscle cells, or even heart cells when needed.
Embryonic stem cells are the ultimate multitaskers because they can become absolutely any cell type. Adult stem cells are more limited – they're found in places like bone marrow and can only make certain types of cells.
The exciting bit is that stem cells could revolutionise medicine. Scientists think they could grow new nerve cells for paralysed people or insulin-producing cells for diabetics. Therapeutic cloning could even create stem cells that match a patient's genes perfectly.
Plants use stem cells too! Meristems in root and shoot tips contain plant stem cells that keep growing throughout the plant's life. Gardeners use this to create identical plant clones quickly and cheaply.
Did You Know You're constantly using stem cells – they're replacing your skin cells, blood cells, and healing your injuries right now!
Your chromosomes are like instruction manuals coiled up inside every cell's nucleus. Humans have 23 pairs (46 total), and each chromosome contains thousands of genes that control everything from your hair colour to your height.
Mitosis is your body's photocopying system for making new cells. Before dividing, each cell copies its DNA completely – this creates those X-shaped chromosomes you see in textbooks where each arm is an identical copy.
During mitosis, chromosomes line up in the cell's centre, then get pulled apart to opposite ends. The cell then splits down the middle, creating two identical cells with exactly the same DNA as the original.
Your body uses mitosis constantly for growth and repair. Every time you get taller, heal a cut, or replace old cells, mitosis is working behind the scenes to keep you healthy.
Fun Fact You make about 25 million new cells every second through mitosis – that's like replacing a small city's population!
Light microscopes let you peek into the cellular world, showing you big structures like nuclei. Electron microscopes are the superheroes of magnification – they reveal tiny details like ribosomes that light microscopes can't see.
The magnification formula (Image size ÷ Real size) helps you work out how much bigger something looks under the microscope. Just make sure both measurements use the same units!
Osmosis is water's natural tendency to move from where there's lots of it to where there's less of it, but only through partially permeable membranes. Think of it like water trying to balance things out by moving through a selective barrier.
Real-Life Example When you put a raisin in water, it swells up because water moves into the raisin through osmosis, trying to dilute the concentrated sugars inside.
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.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
cytoskeleton
BiologyParts of a microscope
BiologyExplanation based on class notes and textbooks about living things in living environments
BiologyA list of Eukaryotic cell organelles and their basic functions
BiologyDescribing the Parts of Microscope with Functions
BiologyBio notes
BiologyApp 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
Billie Bowen
@billiebowen_jqah
Atoms, cells, and microscopes might seem complicated, but they're actually the building blocks that make up everything around you – including you! Understanding these basic concepts will help you ace your science tests and see how amazing the microscopic world... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered what makes gold different from carbon? It's all about elements – substances made up of atoms that have the same number of protons in their nucleus. Think of elements as the pure ingredients of everything in the universe.
The atomic number tells you exactly what element you're dealing with because it counts the protons. If you change the number of protons, you get a completely different element – it's like nature's ID card system.
Isotopes are basically twins with different weights. Carbon-12 and carbon-13 are both carbon (same number of protons), but carbon-13 has an extra neutron making it slightly heavier. Scientists use these to calculate relative atomic mass, which is just the average weight considering all the different isotopes.
Quick Tip: Remember that protons determine the element type – everything else can vary!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Atoms are incredibly tiny – about 0.1 nanometers across – but they're perfectly organised little worlds. Picture a football stadium where the nucleus (containing protons and neutrons) is like a marble in the centre, whilst electrons zoom around the edges.
The nucleus packs almost all the atom's weight into a space 10,000 times smaller than the whole atom. Protons are heavy and positive, neutrons are heavy but neutral, and electrons are tiny with a negative charge.
Here's the clever bit: atoms are normally neutral because they have equal numbers of protons and electrons. When atoms become ions (charged particles), they've either gained or lost electrons. Add electrons for negative ions, lose them for positive ones.
Memory Trick: Electrons are on the outside, so they're the ones that can escape or join – protons stay put in the nucleus!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Stem cells are like biological shape-shifters – they can transform into any type of cell your body needs. Imagine having a bunch of blank cells that could become brain cells, muscle cells, or even heart cells when needed.
Embryonic stem cells are the ultimate multitaskers because they can become absolutely any cell type. Adult stem cells are more limited – they're found in places like bone marrow and can only make certain types of cells.
The exciting bit is that stem cells could revolutionise medicine. Scientists think they could grow new nerve cells for paralysed people or insulin-producing cells for diabetics. Therapeutic cloning could even create stem cells that match a patient's genes perfectly.
Plants use stem cells too! Meristems in root and shoot tips contain plant stem cells that keep growing throughout the plant's life. Gardeners use this to create identical plant clones quickly and cheaply.
Did You Know: You're constantly using stem cells – they're replacing your skin cells, blood cells, and healing your injuries right now!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your chromosomes are like instruction manuals coiled up inside every cell's nucleus. Humans have 23 pairs (46 total), and each chromosome contains thousands of genes that control everything from your hair colour to your height.
Mitosis is your body's photocopying system for making new cells. Before dividing, each cell copies its DNA completely – this creates those X-shaped chromosomes you see in textbooks where each arm is an identical copy.
During mitosis, chromosomes line up in the cell's centre, then get pulled apart to opposite ends. The cell then splits down the middle, creating two identical cells with exactly the same DNA as the original.
Your body uses mitosis constantly for growth and repair. Every time you get taller, heal a cut, or replace old cells, mitosis is working behind the scenes to keep you healthy.
Fun Fact: You make about 25 million new cells every second through mitosis – that's like replacing a small city's population!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Light microscopes let you peek into the cellular world, showing you big structures like nuclei. Electron microscopes are the superheroes of magnification – they reveal tiny details like ribosomes that light microscopes can't see.
The magnification formula (Image size ÷ Real size) helps you work out how much bigger something looks under the microscope. Just make sure both measurements use the same units!
Osmosis is water's natural tendency to move from where there's lots of it to where there's less of it, but only through partially permeable membranes. Think of it like water trying to balance things out by moving through a selective barrier.
Real-Life Example: When you put a raisin in water, it swells up because water moves into the raisin through osmosis, trying to dilute the concentrated sugars inside.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
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.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
cytoskeleton
BiologyParts of a microscope
BiologyExplanation based on class notes and textbooks about living things in living environments
BiologyA list of Eukaryotic cell organelles and their basic functions
BiologyDescribing the Parts of Microscope with Functions
BiologyBio notes
BiologyApp 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
Physics
Sociology