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BiologyBiology1,364 views·Updated Jun 19, 2026·5 pages

Comprehensive Biology Revision: Paper 1 Foundation & Higher

D
Darcy Smyth@darcysmyth_aadg

B1-B4 Biology covers the fundamental concepts of how living things...

1
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

Cells and Transport

Every living thing is built from cells - think of them as biological building blocks with specific parts doing different jobs. Animal cells have a nucleus (containing genetic material), cytoplasm (full of enzymes), cell membrane (controlling what enters and exits), and mitochondria (powering the cell through respiration).

Plant cells have all these parts plus some extras: a cell wall for support, a vacuole filled with cell sap, and chloroplasts for photosynthesis. Some cells, like stem cells found in bone marrow, haven't specialised yet and can become any type of cell - that's why they're so useful in medicine.

Substances move around cells through different processes. Diffusion happens when particles spread from areas of high concentration to low concentration naturally. Osmosis is similar but specifically for water moving across membranes. Active transport is different - it moves molecules against the concentration gradient, which requires energy from the cell.

Quick Tip: Remember that plant cells have everything animal cells have, PLUS extra structures - never the other way around!

2
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

Organs and Enzymes

Your body's organs are perfectly designed for their jobs through specialised exchange surfaces. The lungs have tiny air sacs called alveoli with huge surface areas and thin walls for efficient gas exchange. Your small intestine has villi - finger-like projections that massively increase surface area for absorbing nutrients quickly.

Enzymes are biological catalysts that speed up reactions without being used up themselves. The main digestive enzymes you need to know are amylase (breaks down starch into sugars), protease (breaks down proteins into amino acids), and lipase (breaks down fats into glycerol and fatty acids).

Your heart pumps blood around your body through three types of blood vessels. Arteries carry blood away from the heart, veins carry blood back to the heart, and capillaries are tiny vessels where substances are exchanged with tissues.

Exam Focus: Learn the enzyme names and what they break down - this comes up frequently in tests!

3
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

Disease and Defence

Pathogens are microorganisms that cause disease, and they come in four main types. Bacteria reproduce rapidly and release toxins, viruses live inside cells and damage them, fungi grow and spread on organisms, and protists are parasites that live off other organisms.

Your body has brilliant defence mechanisms against disease. Physical barriers like skin, hair, and mucus stop pathogens entering. If they do get in, white blood cells either consume the invaders or produce antibodies that attack specific pathogens.

Vaccination works by injecting small amounts of dead or inactive pathogens, making your immune system familiar with the disease so it can fight it off quickly if you encounter it again. Antibiotics kill bacteria but don't work against viruses - that's why doctors won't give them for colds or flu.

Real World: Antibiotic-resistant bacteria develop when people don't complete their antibiotic courses, so always finish the full prescription!

4
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

Respiration and Photosynthesis

Respiration happens in every living cell to transfer energy from glucose - it's how your body powers everything from muscle contractions to maintaining body temperature. Aerobic respiration uses oxygen and happens in the mitochondria, whilst anaerobic respiration happens without oxygen but only provides energy for short periods.

Photosynthesis is how plants make their own food using the equation: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂. Plants use the glucose produced for respiration, making cellulose for structure, or storing it as starch for later.

The rate of photosynthesis depends on limiting factors - whichever factor is in shortest supply limits the whole process. These are light intensity, carbon dioxide concentration, and temperature. Farmers use greenhouses to control these factors and maximise crop growth.

Memory Trick: Photosynthesis and respiration are basically opposite processes - one makes glucose using CO₂, the other breaks down glucose producing CO₂!

5
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

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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.

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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 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.

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BiologyBiology1,364 views·Updated Jun 19, 2026·5 pages

Comprehensive Biology Revision: Paper 1 Foundation & Higher

D
Darcy Smyth@darcysmyth_aadg

B1-B4 Biology covers the fundamental concepts of how living things work, from the tiny cells that make up everything to the complex processes that keep organisms alive. You'll explore how substances move in and out of cells, how organs are...

1
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

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

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

Cells and Transport

Every living thing is built from cells - think of them as biological building blocks with specific parts doing different jobs. Animal cells have a nucleus (containing genetic material), cytoplasm (full of enzymes), cell membrane (controlling what enters and exits), and mitochondria (powering the cell through respiration).

Plant cells have all these parts plus some extras: a cell wall for support, a vacuole filled with cell sap, and chloroplasts for photosynthesis. Some cells, like stem cells found in bone marrow, haven't specialised yet and can become any type of cell - that's why they're so useful in medicine.

Substances move around cells through different processes. Diffusion happens when particles spread from areas of high concentration to low concentration naturally. Osmosis is similar but specifically for water moving across membranes. Active transport is different - it moves molecules against the concentration gradient, which requires energy from the cell.

Quick Tip: Remember that plant cells have everything animal cells have, PLUS extra structures - never the other way around!

2
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

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

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

Organs and Enzymes

Your body's organs are perfectly designed for their jobs through specialised exchange surfaces. The lungs have tiny air sacs called alveoli with huge surface areas and thin walls for efficient gas exchange. Your small intestine has villi - finger-like projections that massively increase surface area for absorbing nutrients quickly.

Enzymes are biological catalysts that speed up reactions without being used up themselves. The main digestive enzymes you need to know are amylase (breaks down starch into sugars), protease (breaks down proteins into amino acids), and lipase (breaks down fats into glycerol and fatty acids).

Your heart pumps blood around your body through three types of blood vessels. Arteries carry blood away from the heart, veins carry blood back to the heart, and capillaries are tiny vessels where substances are exchanged with tissues.

Exam Focus: Learn the enzyme names and what they break down - this comes up frequently in tests!

3
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

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

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

Disease and Defence

Pathogens are microorganisms that cause disease, and they come in four main types. Bacteria reproduce rapidly and release toxins, viruses live inside cells and damage them, fungi grow and spread on organisms, and protists are parasites that live off other organisms.

Your body has brilliant defence mechanisms against disease. Physical barriers like skin, hair, and mucus stop pathogens entering. If they do get in, white blood cells either consume the invaders or produce antibodies that attack specific pathogens.

Vaccination works by injecting small amounts of dead or inactive pathogens, making your immune system familiar with the disease so it can fight it off quickly if you encounter it again. Antibiotics kill bacteria but don't work against viruses - that's why doctors won't give them for colds or flu.

Real World: Antibiotic-resistant bacteria develop when people don't complete their antibiotic courses, so always finish the full prescription!

4
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

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

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

Respiration and Photosynthesis

Respiration happens in every living cell to transfer energy from glucose - it's how your body powers everything from muscle contractions to maintaining body temperature. Aerobic respiration uses oxygen and happens in the mitochondria, whilst anaerobic respiration happens without oxygen but only provides energy for short periods.

Photosynthesis is how plants make their own food using the equation: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂. Plants use the glucose produced for respiration, making cellulose for structure, or storing it as starch for later.

The rate of photosynthesis depends on limiting factors - whichever factor is in shortest supply limits the whole process. These are light intensity, carbon dioxide concentration, and temperature. Farmers use greenhouses to control these factors and maximise crop growth.

Memory Trick: Photosynthesis and respiration are basically opposite processes - one makes glucose using CO₂, the other breaks down glucose producing CO₂!

5
of 5
active transport
- movement of molecules across
a cell membrane from region
of lower to a higher
concentration against the
concentration gra

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

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

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.

Most popular content: Protein

9

Most popular content in Biology

9

Most popular content

9
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.

12102,8693,040
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.

1273,6612,307
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.

1254,8691,059
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.

1251,6541,399
C
BiologyBiology

Cell Biology and Cell structure

cell structures

93,2470
English LiteratureEnglish Literature

An Inspector Calls: Character Insights

Explore in-depth analysis and key quotes for characters in J.B. Priestley's 'An Inspector Calls'. This resource covers Gerald Croft, Inspector Goole, Sheila Birling, Mrs. Birling, Eric Birling, and Eva Smith, focusing on themes of class, gender roles, and social responsibility. Ideal for students aiming for Grade 8 and above.

1025,429907
CriminologyCriminology

WJEC Unit 4 Criminology

Criminology unit 4 detailed revision note

127,151125
CriminologyCriminology

Criminology Theories Overview

Explore key criminology theories and their implications on crime and deviance. This comprehensive summary covers biological, psychological, and sociological perspectives, including labelling theory, right realism, and the impact of social campaigns on policy development. Ideal for A-Level criminology students seeking to understand the complexities of criminal behaviour and the factors influencing crime prevention strategies.

129,760210
English LiteratureEnglish Literature

Romeo and Juliet: Key themes

Key Romeo and Juliet themes and analysed quotes

106,708198

Can't find what you're looking for? Explore other subjects.

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