Biology
Chemistry
AP Chemistry
English
AP English Literature
2
0
Sarah
11/22/2025
Biology
Bacteria
77
•
Nov 22, 2025
•
Bacteria are fascinating single-celled organisms that exist all around us... Show more
Bacteria are single-celled prokaryotes (organisms without a nucleus) divided into two kingdoms: Archaebacteria and Eubacteria. Their structure includes internal components like the nucleoid and DNA, surface structures such as the capsule and cell wall, and appendages like pili and flagellum that help with movement and attachment.
You can recognize bacteria by their distinctive shapes: spherical (coccus), rod-shaped (bacillus), or spiral (spirillum). These shapes aren't just interesting to look at—they help scientists identify different bacterial species.
Bacteria reproduce incredibly quickly through a process called binary fission. During binary fission, bacterial DNA is copied, the cell membrane elongates, and eventually pinches off to create two genetically identical daughter cells. This asexual reproduction method explains how bacteria can multiply so rapidly when conditions are right.
Did You Know? Some bacteria can divide every 20 minutes under ideal conditions. At this rate, a single bacterium could theoretically produce over one billion offspring in just 10 hours!
Bacteria can also exchange genetic material through several methods of genetic recombination. During conjugation, a special structure called a sex pilus connects two bacterial cells, allowing a plasmid (small circular DNA) to transfer from one bacterium to another.
Beyond conjugation, bacteria can acquire new genes through two other fascinating processes. During transformation, bacteria pick up DNA from their environment (often from dead bacteria) and incorporate it into their own genome. In transduction, viruses accidentally package bacterial DNA during infection and transfer it to new bacterial hosts.
These genetic exchange methods give bacteria incredible adaptability. When you hear about "superbugs" in the news, you're learning about bacteria that have acquired resistance genes through these processes!
Bacteria play crucial roles in our world. They benefit the environment through nutrient cycling, aid in our digestion, serve as tools in genetic engineering, and help produce many foods like yogurt and cheese. Unfortunately, some bacteria are pathogens that cause infections and diseases.
Remember This: Not all bacteria are harmful! In fact, your body contains trillions of beneficial bacteria that help keep you healthy by aiding digestion and preventing harmful microbes from establishing themselves.
The study of bacteria has a rich history. Anton Van Leeuwenhoek first observed bacteria in 1676, while Louis Pasteur disproved spontaneous generation and developed the germ theory of disease in 1859. Robert Koch created tests to assess the germ theory in 1890, and Paul Ehrlich developed the first synthetic antibiotic by 1910.
Pathogenic bacteria cause diseases through several mechanisms: efficient transmission between hosts, protective coverings that shield them from immune responses, exchange of genetic material (including virulence factors), and rapid reproduction. Examples of bacterial infections include strep throat (caused by Streptococcus pyogenes) and acne (caused by Propionibacterium acnes).
Fortunately, most bacterial infections can be controlled by your immune system or treated with antibiotics. However, we're facing a growing global challenge: antibiotic resistance. This occurs when bacteria evolve the ability to survive exposure to antibiotics that once killed them.
The overuse and misuse of antibiotics has accelerated this problem, leading to the emergence of "superbugs" like MRSA . These resistant bacteria are much harder to treat and can cause serious, sometimes life-threatening infections.
Important Warning: Always take antibiotics exactly as prescribed by your doctor. Never skip doses, stop early, or save antibiotics for later use. These practices contribute to antibiotic resistance.
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
Bacteria are fascinating single-celled organisms that exist all around us and even inside our bodies. Despite their tiny size, these prokaryotes play crucial roles in our environment, health, and daily life—sometimes beneficial, sometimes harmful. Let's explore their structure, reproduction methods,... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Bacteria are single-celled prokaryotes (organisms without a nucleus) divided into two kingdoms: Archaebacteria and Eubacteria. Their structure includes internal components like the nucleoid and DNA, surface structures such as the capsule and cell wall, and appendages like pili and flagellum that help with movement and attachment.
You can recognize bacteria by their distinctive shapes: spherical (coccus), rod-shaped (bacillus), or spiral (spirillum). These shapes aren't just interesting to look at—they help scientists identify different bacterial species.
Bacteria reproduce incredibly quickly through a process called binary fission. During binary fission, bacterial DNA is copied, the cell membrane elongates, and eventually pinches off to create two genetically identical daughter cells. This asexual reproduction method explains how bacteria can multiply so rapidly when conditions are right.
Did You Know? Some bacteria can divide every 20 minutes under ideal conditions. At this rate, a single bacterium could theoretically produce over one billion offspring in just 10 hours!
Bacteria can also exchange genetic material through several methods of genetic recombination. During conjugation, a special structure called a sex pilus connects two bacterial cells, allowing a plasmid (small circular DNA) to transfer from one bacterium to another.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Beyond conjugation, bacteria can acquire new genes through two other fascinating processes. During transformation, bacteria pick up DNA from their environment (often from dead bacteria) and incorporate it into their own genome. In transduction, viruses accidentally package bacterial DNA during infection and transfer it to new bacterial hosts.
These genetic exchange methods give bacteria incredible adaptability. When you hear about "superbugs" in the news, you're learning about bacteria that have acquired resistance genes through these processes!
Bacteria play crucial roles in our world. They benefit the environment through nutrient cycling, aid in our digestion, serve as tools in genetic engineering, and help produce many foods like yogurt and cheese. Unfortunately, some bacteria are pathogens that cause infections and diseases.
Remember This: Not all bacteria are harmful! In fact, your body contains trillions of beneficial bacteria that help keep you healthy by aiding digestion and preventing harmful microbes from establishing themselves.
The study of bacteria has a rich history. Anton Van Leeuwenhoek first observed bacteria in 1676, while Louis Pasteur disproved spontaneous generation and developed the germ theory of disease in 1859. Robert Koch created tests to assess the germ theory in 1890, and Paul Ehrlich developed the first synthetic antibiotic by 1910.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Pathogenic bacteria cause diseases through several mechanisms: efficient transmission between hosts, protective coverings that shield them from immune responses, exchange of genetic material (including virulence factors), and rapid reproduction. Examples of bacterial infections include strep throat (caused by Streptococcus pyogenes) and acne (caused by Propionibacterium acnes).
Fortunately, most bacterial infections can be controlled by your immune system or treated with antibiotics. However, we're facing a growing global challenge: antibiotic resistance. This occurs when bacteria evolve the ability to survive exposure to antibiotics that once killed them.
The overuse and misuse of antibiotics has accelerated this problem, leading to the emergence of "superbugs" like MRSA . These resistant bacteria are much harder to treat and can cause serious, sometimes life-threatening infections.
Important Warning: Always take antibiotics exactly as prescribed by your doctor. Never skip doses, stop early, or save antibiotics for later use. These practices contribute to antibiotic resistance.
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.
2
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Discussed here are the characteristics of living things, big ideas in biology, information and heredity, and unity and diversity of life.
BiologyExplore the classification of living organisms, including vertebrates and invertebrates. This summary covers key groups such as mammals, birds, reptiles, amphibians, and various invertebrate categories like arthropods and molluscs. Understand the characteristics that define each group and their relationships within the biological classification system.
BiologyExplore the essential components of the musculoskeletal system, including tissue and organ functions, joint types, and muscle interactions. This summary covers key concepts such as the role of the skeleton in supporting the body, protecting organs, and facilitating movement. Ideal for exam preparation and understanding human anatomy.
BiologyDescription of the different types of blood cells and all about blood clotting, blood transfusion and blood typing.
BiologyLecture on Fungi
BiologyExplore the fundamentals of health and disease, focusing on pathogens including bacteria, viruses, fungi, and protists. This summary covers how diseases spread, the role of microorganisms in health, and key concepts in infectious disease biology. Ideal for students studying general pathophysiology and microbiology.
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
