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The Best IB Biology Study Guide and Notes for SL/HL

Posted by Dora Seigel | Jul 11, 2015 7:55:03 PM

International Baccalaureate (IB)



IB Biology is challenging, College-level biology, so sometimes you will need a little more study help than your class notes provide. In this article, I compile the best FREE online IB Biology Study Guides (including IB Biology Notes and IB Biology Revision) into one useable resource and provide you with some IB Biology practice questions. I will order this IB Biology Study Guide using the IB Biology Syllabus.


How to use this IB Biology Study Guide

If there is a single topic you are interested in learning more about, use the Command + F function on your computer to search the article for that term. For example, if you want to learn more about Cell Theory, use Command + F to bring up the search function. Type in “Cell Theory” and it will bring up all of the study materials for Cell Theory.

If you are looking for general quiz material for the whole IB Biology Exam, you can skip to the end of the article to the Overall Reviews section for great overall study resources.

First, I will delve into resources by IB Biology Topic. I will separate the resources into:

  • Quick Reference: one-page summary of material if you just need a quick refresher.
  • Longer Notes: notes (generally 3-10 pages) if you need more of an in-depth explanation.
  • Slideshow: powerpoint-type presentation on the material.
  • Video: demonstration videos on how to solve problems related to the material.


How should you use this guide throughout the year?

You should use this guide throughout the year as a refresher before tests and quizzes or for additional support if you did not entirely understand a specific lesson in your IB Biology class. If you still need more assistance, check out our article on the Best IB Biology Books, Reviewed (Coming Soon!). You should be studying throughout the year and not waiting to cram before the IB Biology exam.   


What are good study practices you should keep in mind throughout the year?

You should be integrating real practice questions with each subject. You can find past IB Biology HL and IB Biology SL papers for sale online from the IBO. Also, if you are struggling to understand the material, you should be studying the corresponding chapter in a review book as you learn that chapter in class. Find great IB Biology books in our other article The Best IB Biology Books, Reviewed (Coming Soon!).




Common mistakes students make when studying for IB Biology 

Many students have a hard time with IB Biology. There is a lot of material to cover and you need to be learning it throughout the year(s) in order to master the IB Biology exam. Some common mistakes students make when studying are:

  • Ignoring subjects you don't understand in class.  
    • If you do not understand it in class, you need to seek more help whether through IB Biology study guides, IB Biology Books (article coming soon!), or through tutoring. 
  • Only worrying about studying a week before the IB Biology Exam. 
    • There is way too much material to cover to learn it all in a week (there is a reason it is spread over 1 to 2 years). Learn the material as you cover it in class. Use this study guide for help understanding the concepts you cover in class: 


Study Guide for the IB Biology SL/HL Core


Statistical Analysis

Command Terms

  • Slideshow: Excellent interactive slideshow that gives you tips and tricks.
  • Knowing the command terms is the most crucial part of the IB Biology Exam. If you do not understand the difference in command terms (such as Draw, Annotate, Outline, Analyze, etc.), you will not be able to answer the questions correctly. 




Topic #1: Cell Biology

1.1 Introduction to cells

1.2 Ultrastructure of cells

  1. A cell is composed of organic molecules.
  2. A cell has DNA as their genetic material.
  3. A cell has a cytoplasm that is surrounded by a membrane.
  4.  A new cell comes from pre-existing cells.

1.3 Membrane structure

1.4 Membrane transport

1.5 The origin of cells

1.6 Cell division


Topic #2: Molecular Biology

2.1 Molecules to metabolism

2.2 Water

2.3 Carbohydrates and lipids

2.4 Proteins

  1. Golgi apparatus - rough endoplasmic reticulum - plasma membrane
  2. Rough endoplasmic reticulum - Golgi apparatus - plasma membrane
  3. Golgi apparatus - lysosome - rough endoplasmic reticulum         
  4. Rough endoplasmic reticulum - lysosome - Golgi apparatus  

2.5 Enzymes

2.6 Structure of DNA and RNA

2.7 DNA replication, transcription and translation

2.8 Cell respiration

2.9 Photosynthesis




Topic #3: Genetics

3.1 Genes

3.2 Chromosomes

3.3 Meiosis

3.4 Inheritance

3.5 Genetic modification and biotechnology

  1. Homozygous dominant
  2. Homozygous recessive
  3. Heterozygous dominant
  4. Heterozygous recessive


Topic #4: Ecology

4.1 Species, communities and ecosystems

4.2 Energy flow

4.3 Carbon cycling

4.4 Climate change

  • Here is an IB Biology question that relates to Ecology: Which of the following describes a community?
  1. A group of organisms living and interacting in the same trophic level
  2. A group of populations living and interacting in a food chain
  3. A group of organisms of the same species living and interacting in an ecosystem
  4. A group of populations living and interacting in an area




Topic #5: Evolution and biodiversity

5.1 Evidence for evolution

5.2 Natural selection

5.3 Classification of biodiversity

5.4 Cladistics


Topic #6: Human physiology

6.1 Digestion and absorption

6.2 The blood system

6.3 Defense against infectious disease

6.4 Gas exchange

6.5 Neurons and synapses

6.6 Hormones, homeostasis and reproduction

  1. Reduced antibody production and increased active lymphocytes
  2. Increased antibody production and decreased red blood cell count
  3. Reduced antibody production and decreased active lymphocytes
  4. Increased antibody production and increased red blood cell count


Additional Higher Level Topics

Topic #7: Nucleic Acids

7.1 DNA structure and replication

7.2 Transcription and gene expression

7.3 Translation




Topic #8: Metabolism, cell respiration and photosynthesis

8.1 Metabolism

8.2 Cell respiration

8.3 Photosynthesis


Topic #9: Plant biology

9.1 Transport in the xylem of plants

9.2 Transport in the phloem of plants

9.3 Growth in plants

9.4 Reproduction in plants


Topic #10: Genetics and evolution

10.1 Meiosis

10.2 Inheritance

10.3 Gene pools and speciation



Topic #11: Animal physiology

11.1 Antibody production and vaccination

11.2 Movement

11.3 The kidney and osmoregulation

11.4 Sexual reproduction



A. Neurobiology and Behavior: Core 

  • A.1 Neural development
  • A.2 The human brain
  • A.3 Perception of stimuli

Additional Higher Level Topics

  • A.4 Innate and learned behavior
  • A.5 Neuropharmacology
  • A.6 Ethology




B. Biotechnology and bioinformatics: Core

  • B.1 Microbiology: organisms in industry
  • B.2 Biotechnology in agriculture
  • B.3 Environmental protection

Additional Higher Level Topics

  • B.4 Medicine
  • B.5 Bioinformatics


Options A and B currently do not have free IB Study Guides available online, but look at our article on IB Biology Books (Coming Soon!) to find books that review these options. 




C. Ecology and conservation: Core

C.1 Species and communities

C.2 Communities and ecosystems

C.3 Impacts of humans on ecosystems

C.4 Conservation of biodiversity

Additional Higher Level Topics

C.5 Population ecology

C.6 Nitrogen and phosphorus cycles


D. Human physiology: Core

D.1 Human nutrition

D.2 Digestion

D.3 Functions of the liver

D.4 The heart

Additional Higher Level Topics

D.5 Hormones and metabolism

D.6 Transport of respiratory gases


Overall Reviews


What’s next?

Learn more about IB Biology:

Learn more about the IB Program through our other articles:


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Dora Seigel
About the Author

As an SAT/ACT tutor, Dora has guided many students to test prep success. She loves watching students succeed and is committed to helping you get there. Dora received a full-tuition merit based scholarship to University of Southern California. She graduated magna cum laude and scored in the 99th percentile on the ACT. She is also passionate about acting, writing, and photography.

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