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Changes in the Biology Guide for 2025 exams

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  • Changes in the Biology Guide for 2025 exams

Introduction

If you are familiar with the DP Biology guide from 2014 for exams between 2016 and 2023 this page will be useful. When you fist look at the new guide the most striking change is the layout of the content. The new guide aims to promote a more conceptual understanding of Biology and to support approaches to teaching which help students to discover the links between topics and to connect their learning to some overarching concepts in Biology. These ideas are not new but the look of the guide is very different, and the titles of the topics too. Don't panic, the content has been reduced overall and much of the Biology is familiar. As always, there are also some new updates which reflect discoveries in Biology and add a little freshness to our teaching.

Underlying philosophy

The new guide aims to promote a more conceptual understanding of Biology and to support approaches to teaching which help students to discover the links between topics and to connect their learning to some common themes or overarching concepts in Biology. These ideas are not new but the look of the guide is new, and the titles of the topics too.

There is an updated IB sciences experimentation guidelines document which gives specific guidance for microbiology experiments, ecology fieldwork, as well as risk assessment, disposal of waste. and the previous guidance on animal experimentation and dissections. The document recognises that experiments with animals, such as choice chambers can be performed ethically by following the guidelines. This all seems to make the document more useful,

External Assessment (Exams)

There are still four assessment objectives upon which both the external and internal assessment are based.
The wording of each objective has changed slightly but essentially there are no major changes to the objectives.

There are no changes to command terms used in exams.

A general understanding of the nature of science can be expected.

The total time for the external examination papers remains the same (SL: 3 hours; HL 4.5 hours)

Notable Changes:

  • Students can use a calculator in Paper 1 (i.e. for the multiple choice questions).
  • The questions on experimental work and skills is now in Section B of paper 1
  • There are only two examination papers for each level.
  • The two exam sessions are more similar in length.
  • The weighting of SL exam papers is now equal to HL papers.

Paper 1: Total time 1.5 hours; total raw mark 55; component weighting 36%

In two booklets completed without interruptions on SL level material only

Section A: 30 multiple choice questions (30 marks)

Section B: Data-based & experimental work questions  (25 marks)

    Paper 2: Total time for paper 1.5 hours, total raw mark 50, component weighting 44%

Short-answer and extended-response questions on standard level material only
One extended-response question (from a choice of two) on standard level material only..

Paper 1: Total time 2 hours; total raw mark 75; component weighting 36%

      In two booklets completed without interruptions on SL and AHL material 

Section A: 40 multiple choice questions (40 marks)

Section B: Data-based & experimental work questions  (35 marks)

     Paper 2: Total time for paper 2.5 hours, total raw mark 80, component weighting 44%

          Data-based questions
          Short-answer and extended-response questions on SL and AHL material
          Two Extended-response questions (from a choice of three) on standard level and additional higher level material.

Internal Assessment (IA)

The Individual investigation (IA) is now called "The scientific investigation".

It still counts for 20% of the overall assessment (with the external assessment counting 80%).

The allocated time of 10 hours remains unchanged

There is more scope for students to collaborate on planning and carrying out in a group of up to three, if they wish.
This means that they can share similar methodologies, provided that each student collects data on different independent or dependent variables differ.

Each student must have their own individual research question.

The maximum overall word count for the written report is 3,000 words and there is clear guidance as to what counts as a word.

The report is now assessed on four criteria. The four criteria have equal weighting - 6 marks giving a total of 24.

  • Research  design,
  • Data analysis,
  • Conclusion
  • Evaluation

The four new criteria have new level descriptors in a best-fit rubric model for assigning the marks.

The equal weighting for each criteria now means that a greater emphasis is placed on concluding and evaluating skills with 50% of the marks allocated for Conclusion and Evaluation.

Skills in the study of Biology

Skills and attitudes in the application of scientific knowledge is important in MYP sciences courses. There is a renewed focus on this development of skills in DP Biology which strengthens the links between MYP and DP.

"Application of skills" is included in many syllabus points which provides guidance on using skills within the programme. There is a clear statement that skills in this sense are not methods of communication or argumentation, but scientific skills of manipulation in experimental techniques, applying mathematics, or using technology to collect data during lab work or to process it afterwards. There is an introductory section that lists speficic skills in each of these areas before elaborating on skills required to investigate ideas using the scientific method. 

Clearly all of this will be very helpful when planning a practical scheme of work.

The syllabus content

One aim of the curriculum review was to reduce the volume of content in the DP Biology guide. I counted 605 understanding points in the 2014 guide, including one option, and only 575 points in the 2023 guide.
If we follow this crude mathematical count that would be 5% less content.

At a first glance there looks to be quite a lot of new content in the 2023 guide compared to the 2014. In some cases a new example illustrates an old point from the 2014 guide, e.g. falsification appears in A1.2.15 in an NOS point, "Chargaff’s data falsified the tetranucleotide hypothesis" [of DNA structure], but there is no mention of falsification of Daveson and Danielli's membrane model in the 2023 guide.

The details required in each of the understanding have been written in detail in the 2023 guide which add statements to the guide and might give the impression of a longer document, but probably doesn't increase content.
This certainly helps teaching and reduces the number of ideas which need understanding that are not specifically stated.

Remember the options have been removed which does reduce the content by 15 hours (SL) and 25 hours (HL). However, there are some nice parts of all four options from the "last teaching 2023" guide which have moved into the SL or the HL course. Many of these are from Option C Ecology, including Ecological succession, Population growth curves and Pollution. There are points about the cardiac cycle from Option D,  Gene knockout approaches to research from Option B, and details of the Brain and Spinal cord from Option A.

Some material has moved from SL to HL and some from HL to SL. This doesn't seem to increase the total content.

Material in the 2025 guide that is not in the 2014 guide "last teaching 2023"

Here are a few examples of new content:

  • A2.1.7    Last universal common ancestor
  • A2.3.1    Structural features common to viruses
  • A2.3.2    Diversity of structure in viruses
  • B1.1.11  Triglycerides in adipose tissues for energy storage and thermal insulation
  • B2.3.3    Stem cell niches
  • B3.3.10  Adaptations for swimmiing in marine mammmals
  • C1.1.17  Mecanism based inhibition..by..irreversible binding of an inhibitor (e.g. penicillin).
  • C1.3.8    Carbon dioxide enrichment experiments
  • C2.2.16  Consciousness - in relation to anasthetics
  • C3.2.15  Zoonoses
  • D1.3.9    Use of the CRISPR sequences and the enzyme Cas9 in gene editing
  • D2.2.10  Monozygotic twin studies
  • D4.3.11  Increases to the number of insect life cycles within a year due to climate change

Changes in terminology

2023 Guide

Scientific investigation

Collaborative sciences project

2014 Guide

Individual investigation

Group 4 project

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