Every living thing around you - from your pet dog...
Introduction to Biology

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.

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...
Similar content
Most popular content: Cell
8Biology: 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.
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.
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.
Biology Higher Tier Notes and CheatSheet
AQA
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.
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.
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.
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.
Most popular content in Biology
9Cell Biology and Cell structure
cell structures
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.
1.cells Gcse biology question cards
combined science higher biology
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.
Types of cells
biology
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.
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.
Biology Paper 1 quiz
this is a simple quiz on key knowledge needed for paper 1
Biology The circulatory system quick recap
All of circulatory system covered easily
Most popular content
9Sociology 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.
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.
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.
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.
Cell Biology and Cell structure
cell structures
WJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
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.
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.
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.
Students love us — and so will you.
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.
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.
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.
Introduction to Biology
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...

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.

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...
Similar content
Most popular content: Cell
8Biology: 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.
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.
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.
Biology Higher Tier Notes and CheatSheet
AQA
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.
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.
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.
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.
Most popular content in Biology
9Cell Biology and Cell structure
cell structures
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.
1.cells Gcse biology question cards
combined science higher biology
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.
Types of cells
biology
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.
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.
Biology Paper 1 quiz
this is a simple quiz on key knowledge needed for paper 1
Biology The circulatory system quick recap
All of circulatory system covered easily
Most popular content
9Sociology 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.
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.
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.
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.
Cell Biology and Cell structure
cell structures
WJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
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.
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.
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.
Students love us — and so will you.
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.
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.
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.