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Jan 20, 2026
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Biology 1 Honors Notes - Unit 1 Overview
Ansley Miller
@ansleymiller
1 / 3
Characteristics of Life
Ever wondered what exactly makes something "alive"? For an organism to be considered living, it must have several key characteristics. All living things are made of one or more cells, which are the basic units of life and the smallest possible organisms. These cells can be either prokaryotic or eukaryotic.
Living organisms must be able to reproduce and pass on their traits. This can happen through sexual reproduction (two parents combining genetic material) or asexual reproduction (one parent creating identical copies). A species is defined as a group that can reproduce together in nature and create fertile offspring.
The universal genetic code in DNA determines what individuals look like and how they function. This code is passed from parents to offspring, explaining why children resemble their parents. DNA is composed of nucleotides that create the blueprint for every living thing.
Quick Fact: Some organisms like mules and certain bananas are exceptions because they can't reproduce in nature, challenging our definition of "species."
Life Processes and Evolution
All living things experience growth and development during their lives. Single-celled organisms typically just grow larger, while multicellular organisms both grow AND develop - changing in structure and function over time. This development begins with a single cell that divides repeatedly.
Energy is essential for life! Organisms must obtain and use energy to survive. Autotrophs (like plants) make their own energy from the sun, while heterotrophs (like animals) get energy by consuming food. This energy powers metabolism - all the chemical reactions needed for life.
Living things must respond to stimuli and maintain homeostasis to survive. Whether it's feeling pain or getting thirsty when dehydrated, organisms react to both internal and external signals. Even as outside conditions change, living things work to keep their internal environment balanced.
Evolution happens as organisms change over time, developing traits better suited to their environments. This occurs through generations as genes mix and beneficial traits are passed on, creating a continuous cycle of dependence where living things rely on each other.
Remember: When you feel thirsty, that's homeostasis in action! Your body is detecting dehydration and prompting you to restore your water balance.
Viruses and Their Life Cycles
Viruses challenge our definition of "living" because they're not made of cells and have no organelles. Scientists classify viruses based on three main characteristics: whether they contain DNA or RNA, the shape of their genetic makeup, and if they have a membranous envelope.
Viruses reproduce by invading cells through a lytic cycle or lysogenic cycle. In the lytic cycle, viruses immediately take over the host cell, rapidly produce new viruses, and then burst the cell to spread. This aggressive approach works quickly but is easier to detect.
The lysogenic cycle is sneakier! The virus integrates its genetic information into the host's DNA, creating a dormant phase. The cell treats the virus as part of its own genetic code, producing one virus at a time. This slower method is harder for the immune system to detect.
Antibiotics don't work against viruses because they only target living organisms. The word "antibiotic" literally means "against life," and since viruses aren't technically alive, these medications have no effect on them. This is why viral infections require different treatments than bacterial ones.
Think About It: Viruses are like computer hackers that can't do anything on their own but can hijack your body's cells to make copies of themselves!
We thought you’d never ask...
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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.
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Anna
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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❗️❗️⚠️
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Brad T
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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
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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.
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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
homepage/newPositiveReviewText6
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
homepage/newPositiveReviewText6
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
Biology 1 Honors Notes - Unit 1 Overview
Ansley Miller
@ansleymiller
Biology is the study of life and living organisms. This unit explores what makes something "living" through specific characteristics, how life maintains and reproduces itself, and examines exceptions like viruses. Understanding these concepts helps us make advances in medicine and... Show more
Characteristics of Life
Ever wondered what exactly makes something "alive"? For an organism to be considered living, it must have several key characteristics. All living things are made of one or more cells, which are the basic units of life and the smallest possible organisms. These cells can be either prokaryotic or eukaryotic.
Living organisms must be able to reproduce and pass on their traits. This can happen through sexual reproduction (two parents combining genetic material) or asexual reproduction (one parent creating identical copies). A species is defined as a group that can reproduce together in nature and create fertile offspring.
The universal genetic code in DNA determines what individuals look like and how they function. This code is passed from parents to offspring, explaining why children resemble their parents. DNA is composed of nucleotides that create the blueprint for every living thing.
Quick Fact: Some organisms like mules and certain bananas are exceptions because they can't reproduce in nature, challenging our definition of "species."
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Life Processes and Evolution
All living things experience growth and development during their lives. Single-celled organisms typically just grow larger, while multicellular organisms both grow AND develop - changing in structure and function over time. This development begins with a single cell that divides repeatedly.
Energy is essential for life! Organisms must obtain and use energy to survive. Autotrophs (like plants) make their own energy from the sun, while heterotrophs (like animals) get energy by consuming food. This energy powers metabolism - all the chemical reactions needed for life.
Living things must respond to stimuli and maintain homeostasis to survive. Whether it's feeling pain or getting thirsty when dehydrated, organisms react to both internal and external signals. Even as outside conditions change, living things work to keep their internal environment balanced.
Evolution happens as organisms change over time, developing traits better suited to their environments. This occurs through generations as genes mix and beneficial traits are passed on, creating a continuous cycle of dependence where living things rely on each other.
Remember: When you feel thirsty, that's homeostasis in action! Your body is detecting dehydration and prompting you to restore your water balance.
Sign up to see the contentIt's free!
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Viruses and Their Life Cycles
Viruses challenge our definition of "living" because they're not made of cells and have no organelles. Scientists classify viruses based on three main characteristics: whether they contain DNA or RNA, the shape of their genetic makeup, and if they have a membranous envelope.
Viruses reproduce by invading cells through a lytic cycle or lysogenic cycle. In the lytic cycle, viruses immediately take over the host cell, rapidly produce new viruses, and then burst the cell to spread. This aggressive approach works quickly but is easier to detect.
The lysogenic cycle is sneakier! The virus integrates its genetic information into the host's DNA, creating a dormant phase. The cell treats the virus as part of its own genetic code, producing one virus at a time. This slower method is harder for the immune system to detect.
Antibiotics don't work against viruses because they only target living organisms. The word "antibiotic" literally means "against life," and since viruses aren't technically alive, these medications have no effect on them. This is why viral infections require different treatments than bacterial ones.
Think About It: Viruses are like computer hackers that can't do anything on their own but can hijack your body's cells to make copies of themselves!
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
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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4.8/5
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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
homepage/newPositiveReviewText6
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
homepage/newPositiveReviewText6
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