IBDP BIOLOGY HL/SL HANDBOOK 

Distinction between SL and HL 

Students at SL and HL share the following.

 • An understanding of science through a stimulating experimental programme

 • The nature of science as an overarching theme 

• The study of a concept-based syllabus

 • One piece of internally assessed work, the scientic investigation

 • The collaborative sciences project The SL course provides students with a fundamental understanding of biology and experience of the associated skills. The HL course requires students to increase their knowledge and understanding of the subject, and so provides a solid foundation for further study at university level. 

The SL course has a recommended 150 teaching hours, compared to 240 hours for the HL course. This difference is reected in the additional content studied by HL students. Some of the HL content is conceptually more demanding and explored in greater depth. The distinction between SL and HL is therefore one of both breadth and depth. The increased breadth and depth at HL result in increased networked knowledge, requiring the student to make more connections between diverse areas of the syllabus 

External assessment details—SL

Paper 1

Duration: 1 hour and 30 minutes

Weighting: 36%

Marks: 55

Paper 1 is presented as two separate booklets

Paper 1A—30 marks

• 30 multiple-choice questions on standard level material.

No marks are deducted for incorrect answers.

Paper 1B—25 marks

• Four data-based questions related to experimental work and the syllabus.

Paper 1A and Paper 1B are to be completed together without interruptions.

The questions on paper 1 test assessment objectives 1, 2 and 3.

The use of calculators is permitted. See the Calculators guidance for examinations booklet on the Programme Resource Centre.

Paper 2

Duration: 1 hour and 30 minutes

Weighting: 44%

Marks: 50

Section A—34 marks

• Data-based question.

• Short-answer questions on standard level material.

Section B—16 marks

• Extended-response questions on standard level material.

One of two extended-response questions to be attempted by candidates.

The questions on paper 2 test assessment objectives 1, 2 and 3.

The use of calculators is permitted. See the Calculators guidance for examinations booklet on the

Programme Resource Centre.

External assessment details—HL

Paper 1

Duration: 2 hours

Weighting: 36%

Marks: 75

Paper 1 is presented as two separate booklets

Paper 1A—40 marks

• 40 multiple-choice questions on standard level and additional higher level material.

No marks are deducted for incorrect answers.

Paper 1B—35 marks

• Four data-based questions related to experimental work and the syllabus.

Paper 1A and Paper 1B are to be completed together without interruptions.

The questions on paper 1 test assessment objectives 1, 2 and 3.

The use of calculators is permitted. See the Calculators guidance for examinations booklet on the Programme Resource Centre.

Paper 2

Duration: 2 hours and 30 minutes

Weighting: 44%

Marks: 80

Section A—48 marks

• Data-based question.

• Short-answer questions on standard level and additional higher level material.

Section B—32 marks

• Extended-response questions on standard level and additional higher level material.

Two of three extended-response questions to be attempted by candidates.

The questions on paper 2 test assessment objectives 1, 2 and 3.

The use of calculators is permitted. See the Calculators guidance for examinations booklet on the Programme Resource Centre.

Internal assessment details—SL and HL

The scientic investigation

Duration: 10 hours

Weighting: 20%

The IA requirement is the same for biology, chemistry and physics. The IA, worth 20% of the nal assessment, consists of one task—the scientific investigation.

The scientic investigation is an open-ended task in which the student gathers and analyses data in

order to answer their own formulated research question.

The outcome of the scientic investigation will be assessed through the form of a written report. The

maximum overall word count for the report is 3,000 words.

The following are not included in the word count.

• Charts and diagrams

• Data tables

• Equations, formulas and calculations

• Citations/references (whether parenthetical, numbered, footnotes or endnotes)

• Bibliography

• Headers

The following details should be stated at the start of the report.

• Title of the investigation

• IB candidate code (alphanumeric, for example, xyz123)

• IB candidate code for all group members (if applicable)

• Number of words

There is no requirement to include a cover page or a contents page.

Facilitating the scientic investigation

The research question should be of interest to the student, but it is not necessary that it encompasses

concepts beyond those described by the understandings within the guide.

The scientic investigation undertaken must have sufficient extent and depth to allow for all the

descriptors of the assessment criteria to be meaningfully addressed.

The investigation of the research question must involve the collection and analysis of quantitative

data that should be supported by qualitative observations where appropriate.

The scientic investigation allows a wide range of techniques for data gathering and analysis to be

employed. The approaches that could be used in isolation or in conjunction with each other are as

follows.

• Hands-on practical laboratory work

• Fieldwork

• Use of a spreadsheet for analysis and modelling

• Extraction and analysis of data from a database

• Use of a simulation.

The Biology teachersupport material contains further guidance on these possible approaches.

Assessing the scientic investigation

The performance in IA at both SL and HL is marked against common assessment criteria, with a total

mark out of 24. Student work is internally assessed by the teacher and externally moderated by the IB.

The four assessment criteria are as follows.

• Research design

• Data analysis

• Conclusion

• Evaluation

Each assessment criterion has level descriptors describing specic achievement levels, together with

an appropriate range of marks. The level descriptors concentrate on positive achievement, although

for the lower levels failure to achieve may be included in the description.

Teachers must judge the internally assessed work at SL and at HL against the same criteria using the

level descriptors and aided by the clarications. The criteria must be applied systematically using a

best-t approach—when a piece of work matches different aspects of a criterion at different levels the

mark awarded should be one that most fairly reects the balance of achievement against the criterion.

It is not necessary for every single aspect of a level descriptor to be met for that mark to be awarded.

The highest level descriptors do not imply faultless performance.

Where there are two or more marks available within a level, teachers should award the upper mark if

the student’s work largely satises the qualities described; the work may be close to achieving marks

in the level above. Teachers should award the lower marks if the student’s work demonstrates the

qualities described to a lesser extent; the work may be close to achieving marks in the level below.

Only whole numbers must be recorded; partial marks (fractions and decimals) are not acceptable.

The criteria should be considered independently. A student who attains a high achievement level in

relation to one criterion will not necessarily attain high achievement levels in relation to the other

criteria. Similarly, a student who attains a low achievement level for one criterion will not necessarily

attain low achievement levels for the other criteria. Teachers should not assume that the overall

assessment of the students will produce any particular distribution of marks.

Where command terms are used in the level descriptors, they are to be interpreted as indicated in

the “Glossary of command terms” section of this guide. These command terms indicate the depth of

treatment required.

Referencing and academic integrity

Appropriate referencing to sourced information used in the report of the scientic investigation is

expected. Omitted or improper referencing will be considered to be academic malpractice.

Students must ensure their assessment work adheres to the IB’s academic integrity policy and that all

sources are appropriately referenced. A student’s failure to appropriately acknowledge a source will be

investigated by the IB as a potential breach of regulations that may result in a penalty imposed by the

IB Final Award Committee. See the “Academic integrity” section of this guide for full details.