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The IB Biology course can feel unpredictable if you’re not fully aware of what it includes. This guide is designed to walk you through the course step by step, making everything easier to understand. We’ll cover the major components of both the internal and external assessments, along with useful advice for writing a Biology Extended Essay if you choose to do your EE in biology.
IB Biology Guide
General Overview
Syllabus – IB Biology helps students understand the complex systems and processes that define living organisms. The course encourages students to explore biological concepts and apply them through practical lab work. Students study topics such as cell biology, genetics, ecology, evolution, human physiology, and molecular biology. For a full overview of the IB Biology syllabus and a breakdown of the topics in each unit, check out this post.
Textbooks – To succeed in IB Biology, students need a thorough understanding of the course concepts. A good textbook is essential to improving your understanding of IB Biology, as it can clearly explain biology theory and provide practice questions to help you develop your skills. Our recommended list of IB textbooks can be found here.
Grade boundaries – Although the IB Biology grade boundaries change from session to session, it is important that you are familiar with what the approximate range of values can be. This can help you, especially when practicing past papers, as it can show you what grade category you fall into depending on the number of marks you obtain. The latest IB grade boundaries can be found here.
General difficulty – IB Biology is considered a mildly challenging science course, as it is easier than both IB Physics and IB Chemistry. For a more in-depth view into how hard IB Biology is, check out this guide.
Getting the maximum score – The ultimate goal of any IB student is to get the highest score possible. To ensure your success in IB Biology, we have compiled some tips to help you get a 7. You can read our suggestions in this post.
Assessment overview – The IB Biology course consists of both external exams and internal assessments, which will be outlined in more depth in the section below. For a summary of the IB Biology assessment and the IB Biology paper weighting, click the links in blue.
External Assessments - Exams
Paper 1 – This paper is split into 2 parts. Part A consists of multiple-choice questions, while Part B is data-based with 4 questions targeting all syllabus themes. More information about the structure, time limit, weighting, and differences between SL and HL for Paper 1 can be found here.
Paper 2 – This paper consists of data-based, short-answer and extended response questions. More information about the structure, time limit, weighting, and differences between SL and HL for Paper 2 can be found here.
Command terms – To succeed in the exams, you must understand what each question type is asking you to do. Command terms such as "Define", "Outline", "Comment", and "Predict" all have different meanings and require you to structure your answer in a certain way. Browse through our list of command terms to understand what each one means.
Formula booklet – While there is no official IB Biology formula booklet, we have compiled a list of formulas that could be useful when doing past papers or studying for the exam. You can access our suggested IB Biology formula booklet here.
Study tips – When studying for exams, you should make use of flashcards, practice past papers, and diagrams. To read some of our top tips on how to study for IB Biology exams, read this post here.
Internal Assessment (IA)
Topic ideas – The Biology IA allows you to explore a certain research question in depth. A Biology IA involves conducting your own experiments and writing a formal lab report. Many topics can be explored in the Biology IA. For a detailed list of topic ideas and examples, read our post here. If you need some help getting started, check out this guide on how to start the Biology IA.
Criteria – The Biology IA is scored against 4 main criteria, such as research design, data analysis, conclusion, and evaluation. For a detailed list of the IB Biology IA criteria and a checklist of what to include to maximize your chances of a 7, check out our guide here.
Format and word count – Biology IAs should include sections such as an introduction, background information, results, conclusion, and evaluation, etc. For a full guide to the format and structure of a Biology IA, including what each section should contain, see this guide. The Biology IA should be a maximum of 3000 words. For a guide on how many words each section should be, read this post here.
Mistakes – Common errors such as incomplete background information, poor data analysis, or limited conclusions can prevent you from getting full marks. Check out our guide to the top 10 mistakes students make in the Biology IA so you can avoid making the same errors in your IA.
Extended Essay (EE)
Topic ideas – The EE is a 4000-word investigation that allows you to explore a certain research question in depth. Most often, a Biology EE involves conducting your own experiments and writing a formal lab report. There is a wide variety of topics you can choose to investigate for your Biology EE. For a detailed list of topic ideas and associated examples, read our post here.
Criteria – The EE is scored against 5 criteria that target different aspects of your investigation, such as critical thinking, presentation and engagement. For a detailed list of the IB Biology EE criteria and a checklist of what to include to maximize your chances of an A in the EE, check out our guide here.
Format – A well-presented EE can drastically improve your score. Biology EEs should include sections such as an introduction, background information, results, evaluation, and conclusion, etc. For a full guide to the format and structure of a Biology EE, including what each section should contain, see this guide.
Comparison to Other Science Subjects
Physics – IB Biology is considered more memorization-based and much less math-heavy than IB Physics. IB Biology is often considered one of the easiest sciences, while IB Physics is one of the most difficult. IB Biology focuses more on wet labs, while the labs in IB Physics can be more practical (e.g. ball rolling down a ramp, dropping a parachute, etc.). For a detailed overview of IB Physics and IB Biology, including a comparison of course content, who should take these courses, and applicable university majors, read this guide.
Chemistry – IB Biology is considered more memorization-based and less math-heavy than IB Chemistry. IB Biology is often considered one of the easier sciences, while IB Chemistry is moderately challenging. Both subjects place a strong emphasis on laboratory skills. For a detailed overview of IB Biology and IB Chemistry, including a comparison of course content, who should take these courses, and applicable university majors, read this guide.
We hope this post has helped you learn more about IB Biology. For more useful materials associated with the IB, check out the wide variety of IA, EE and TOK exemplars available at Clastify and other guides available on our blog.
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