Open the App

Subjects

BiologyBiology51 views·Updated 7 Aug 2026·2 pages

Introduction to Biology

M
maddie@xxmaddiexx

Every living thing around you - from your pet dog...

1
of 2
Biology – page 1

What Are Cells and How Do They Work?

Think of cells as microscopic boxes that contain everything needed for life. Each cell is basically a blob of jelly-like cytoplasm wrapped up in a protective cell membrane that acts like a bouncer at a club - it decides what gets in and what stays out.

Some living things, like bacteria, are just single cells doing everything on their own. Others, like you, are made of billions of cells working together as a team. Every cell needs a control centre called the nucleus, which stores all the DNA instructions for how the cell should behave.

The cell membrane is incredibly clever - it's not just a wall, but more like a smart gate. It lets essential nutrients flow in whilst pushing waste products out, and even helps cells chat to each other about what's happening in their environment.

Quick Tip: Remember that animal cells have loads of different parts (organelles) working together, just like how your school has different departments all doing their own jobs to keep everything running smoothly.

2
of 2
Biology – page 2

Plant Cells vs Animal Cells and Cell Division

Plant cells are quite similar to animal cells, but they've got some extra features that make them special. They have a tough cell wall for support (like wearing armour), a massive vacuole that helps keep the plant upright, and chloroplasts where photosynthesis happens to make food from sunlight.

When it comes to making new cells, there are three main ways this happens. Mitosis is like a photocopier - it makes exact copies of cells for growth and repair. Meiosis is different because it creates egg and sperm cells that have only half the usual DNA, ready for reproduction.

Binary fission is the simplest method, used by bacteria. They just split themselves in two, like dividing a pizza. Each type of cell division serves a different purpose, but they all ensure life continues.

Remember: Plant cells = animal cells + cell wall + big vacuole + chloroplasts. It's that simple!

We thought you’d never ask...

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

You can download the app from Google Play Store and Apple App Store.

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Similar content

Most popular content: Cell

8
BiologyBiology

Biology: Cell & Tissue Dynamics

Explore the intricate structures and functions of cells and tissues in this comprehensive overview of Biology Unit 1. This study note covers key concepts such as membrane potential, synaptic transmission, blood circulation, and muscle physiology, providing essential insights into the human body and its systems. Ideal for students preparing for exams in Applied Science.

121,79320
BiologyBiology

Cell Biology Overview

Explore the fundamental concepts of cell biology, including prokaryotic and eukaryotic cells, cell specialization, and the organization of tissues and organs. This summary covers the advantages of light and electron microscopes, key cellular structures, and the processes of cell differentiation. Ideal for GCSE Biology students preparing for exams.

1175027
BiologyBiology

Cell Structure Overview

Explore the fundamental components of animal and plant cells, including organelles, cell membranes, and their functions. This summary covers key concepts such as eukaryotic and prokaryotic cell structures, the role of the nucleus, mitochondria, chloroplasts, and more. Ideal for AS-level biology students.

121841
BiologyBiology

Biology Higher Tier Notes and CheatSheet

AQA

114085
BiologyBiology

Cell Structure Overview

Explore the essential components of cell structure in this detailed summary. Understand the differences between prokaryotic and eukaryotic cells, the functions of organelles, and the processes of cell division and differentiation. Ideal for Nat 5 Biology students preparing for exams.

S31,03331
BiologyBiology

Cell Biology & Microscopy

Comprehensive overview of cell biology and microscopy techniques, including detailed explanations of eukaryotic and prokaryotic cells, subcellular structures, and a step-by-step guide on preparing microscope slides. Ideal for AQA GCSE Combined Science Higher Tier students.

113652
BiologyBiology

Animal Cell Structures

Explore the three main structures of animal cells: the nucleus, cell membrane, and cytoplasm. This summary covers their functions, how to observe them under a microscope, and includes practical activities for hands-on learning. Ideal for students studying cellular biology.

S11552
BiologyBiology

Cell Biology Essentials

Explore key concepts in cell biology, including prokaryotic and eukaryotic cells, cellular structures, and functions. This resource covers the roles of organelles, muscle tissue types, and the mechanisms of synaptic transmission. Ideal for BTEC Level 3 Applied Science students seeking a comprehensive understanding of biological cells and their functions.

1257513

Most popular content in Biology

9
C
BiologyBiology

Cell Biology and Cell structure

cell structures

113,3220
T
BiologyBiology

The functions of subcellular structures - B1 Biology

Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.

112,8215
1
BiologyBiology

1.cells Gcse biology question cards

combined science higher biology

92,3854
BiologyBiology

A-Level Biology Year 1 Overview

Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.

1214,997698
T
BiologyBiology

Types of cells

biology

101,2280
BiologyBiology

Biology P2: Evolution & Adaptation

Explore key concepts in AQA GCSE Biology P2, focusing on evolution, natural selection, genetic engineering, and adaptations in organisms. This summary covers essential topics such as DNA structure, speciation, and the impact of environmental changes on biodiversity. Ideal for exam preparation and understanding complex biological processes.

111,23722
BiologyBiology

AQA Biology: Key Concepts

Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.

108,987309
B
BiologyBiology

Biology Paper 1 quiz

this is a simple quiz on key knowledge needed for paper 1

112,7855
B
BiologyBiology

Biology The circulatory system quick recap

All of circulatory system covered easily

119431

Most popular content

9
SociologySociology

Sociology of Families: Comprehensive Revision

Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.

1273,8302,306
SociologySociology

Comprehensive Crime & Deviance Overview

Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.

1251,6881,401
CriminologyCriminology

Criminology: Crime & Punishment Overview

Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.

1254,9081,061
SociologySociology

Sociology of Education Overview

Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.

12103,0093,041
C
BiologyBiology

Cell Biology and Cell structure

cell structures

113,3220
CriminologyCriminology

WJEC Unit 4 Criminology

Criminology unit 4 detailed revision note

127,182125
English LanguageEnglish Language

Language Paper 1 Strategies

Master the AQA English Language Paper 1 with this comprehensive guide. Explore key strategies for language and structural analysis, critical evaluation, and creative writing. Learn how to effectively analyze texts, utilize literary techniques, and enhance your writing skills to excel in your exams.

928,577896
SociologySociology

Media Studies: Key Concepts & Theories

Dive into the essential concepts and theories of media studies for AQA A-level Sociology. This comprehensive revision guide covers topics such as media influence, representations, globalization, and sociological perspectives, ensuring you grasp the critical elements needed for your exams. Perfect for students seeking to enhance their understanding of media's role in society.

1222,744514
SociologySociology

Sociological Theories Overview

Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.

1231,511846

Students love us — and so will you.

4.6/5App Store
4.7/5Google 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 SiOS 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 KlichAndroid 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.

AnnaiOS user

BiologyBiology51 views·Updated 7 Aug 2026·2 pages

Introduction to Biology

M
maddie@xxmaddiexx

Every living thing around you - from your pet dog to the plants in your garden - is made up of tiny building blocks called cells. Understanding how these cells work and divide is crucial for grasping how life itself...

1
of 2
Biology – page 1

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

By signing up you accept Terms of Service and Privacy Policy

What Are Cells and How Do They Work?

Think of cells as microscopic boxes that contain everything needed for life. Each cell is basically a blob of jelly-like cytoplasm wrapped up in a protective cell membrane that acts like a bouncer at a club - it decides what gets in and what stays out.

Some living things, like bacteria, are just single cells doing everything on their own. Others, like you, are made of billions of cells working together as a team. Every cell needs a control centre called the nucleus, which stores all the DNA instructions for how the cell should behave.

The cell membrane is incredibly clever - it's not just a wall, but more like a smart gate. It lets essential nutrients flow in whilst pushing waste products out, and even helps cells chat to each other about what's happening in their environment.

Quick Tip: Remember that animal cells have loads of different parts (organelles) working together, just like how your school has different departments all doing their own jobs to keep everything running smoothly.

2
of 2
Biology – page 2

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Plant Cells vs Animal Cells and Cell Division

Plant cells are quite similar to animal cells, but they've got some extra features that make them special. They have a tough cell wall for support (like wearing armour), a massive vacuole that helps keep the plant upright, and chloroplasts where photosynthesis happens to make food from sunlight.

When it comes to making new cells, there are three main ways this happens. Mitosis is like a photocopier - it makes exact copies of cells for growth and repair. Meiosis is different because it creates egg and sperm cells that have only half the usual DNA, ready for reproduction.

Binary fission is the simplest method, used by bacteria. They just split themselves in two, like dividing a pizza. Each type of cell division serves a different purpose, but they all ensure life continues.

Remember: Plant cells = animal cells + cell wall + big vacuole + chloroplasts. It's that simple!

We thought you’d never ask...

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

You can download the app from Google Play Store and Apple App Store.

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Similar content

Most popular content: Cell

8
BiologyBiology

Biology: Cell & Tissue Dynamics

Explore the intricate structures and functions of cells and tissues in this comprehensive overview of Biology Unit 1. This study note covers key concepts such as membrane potential, synaptic transmission, blood circulation, and muscle physiology, providing essential insights into the human body and its systems. Ideal for students preparing for exams in Applied Science.

121,79320
BiologyBiology

Cell Biology Overview

Explore the fundamental concepts of cell biology, including prokaryotic and eukaryotic cells, cell specialization, and the organization of tissues and organs. This summary covers the advantages of light and electron microscopes, key cellular structures, and the processes of cell differentiation. Ideal for GCSE Biology students preparing for exams.

1175027
BiologyBiology

Cell Structure Overview

Explore the fundamental components of animal and plant cells, including organelles, cell membranes, and their functions. This summary covers key concepts such as eukaryotic and prokaryotic cell structures, the role of the nucleus, mitochondria, chloroplasts, and more. Ideal for AS-level biology students.

121841
BiologyBiology

Biology Higher Tier Notes and CheatSheet

AQA

114085
BiologyBiology

Cell Structure Overview

Explore the essential components of cell structure in this detailed summary. Understand the differences between prokaryotic and eukaryotic cells, the functions of organelles, and the processes of cell division and differentiation. Ideal for Nat 5 Biology students preparing for exams.

S31,03331
BiologyBiology

Cell Biology & Microscopy

Comprehensive overview of cell biology and microscopy techniques, including detailed explanations of eukaryotic and prokaryotic cells, subcellular structures, and a step-by-step guide on preparing microscope slides. Ideal for AQA GCSE Combined Science Higher Tier students.

113652
BiologyBiology

Animal Cell Structures

Explore the three main structures of animal cells: the nucleus, cell membrane, and cytoplasm. This summary covers their functions, how to observe them under a microscope, and includes practical activities for hands-on learning. Ideal for students studying cellular biology.

S11552
BiologyBiology

Cell Biology Essentials

Explore key concepts in cell biology, including prokaryotic and eukaryotic cells, cellular structures, and functions. This resource covers the roles of organelles, muscle tissue types, and the mechanisms of synaptic transmission. Ideal for BTEC Level 3 Applied Science students seeking a comprehensive understanding of biological cells and their functions.

1257513

Most popular content in Biology

9
C
BiologyBiology

Cell Biology and Cell structure

cell structures

113,3220
T
BiologyBiology

The functions of subcellular structures - B1 Biology

Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.

112,8215
1
BiologyBiology

1.cells Gcse biology question cards

combined science higher biology

92,3854
BiologyBiology

A-Level Biology Year 1 Overview

Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.

1214,997698
T
BiologyBiology

Types of cells

biology

101,2280
BiologyBiology

Biology P2: Evolution & Adaptation

Explore key concepts in AQA GCSE Biology P2, focusing on evolution, natural selection, genetic engineering, and adaptations in organisms. This summary covers essential topics such as DNA structure, speciation, and the impact of environmental changes on biodiversity. Ideal for exam preparation and understanding complex biological processes.

111,23722
BiologyBiology

AQA Biology: Key Concepts

Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.

108,987309
B
BiologyBiology

Biology Paper 1 quiz

this is a simple quiz on key knowledge needed for paper 1

112,7855
B
BiologyBiology

Biology The circulatory system quick recap

All of circulatory system covered easily

119431

Most popular content

9
SociologySociology

Sociology of Families: Comprehensive Revision

Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.

1273,8302,306
SociologySociology

Comprehensive Crime & Deviance Overview

Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.

1251,6881,401
CriminologyCriminology

Criminology: Crime & Punishment Overview

Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.

1254,9081,061
SociologySociology

Sociology of Education Overview

Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.

12103,0093,041
C
BiologyBiology

Cell Biology and Cell structure

cell structures

113,3220
CriminologyCriminology

WJEC Unit 4 Criminology

Criminology unit 4 detailed revision note

127,182125
English LanguageEnglish Language

Language Paper 1 Strategies

Master the AQA English Language Paper 1 with this comprehensive guide. Explore key strategies for language and structural analysis, critical evaluation, and creative writing. Learn how to effectively analyze texts, utilize literary techniques, and enhance your writing skills to excel in your exams.

928,577896
SociologySociology

Media Studies: Key Concepts & Theories

Dive into the essential concepts and theories of media studies for AQA A-level Sociology. This comprehensive revision guide covers topics such as media influence, representations, globalization, and sociological perspectives, ensuring you grasp the critical elements needed for your exams. Perfect for students seeking to enhance their understanding of media's role in society.

1222,744514
SociologySociology

Sociological Theories Overview

Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.

1231,511846

Students love us — and so will you.

4.6/5App Store
4.7/5Google 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 SiOS 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 KlichAndroid 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.

AnnaiOS user