IBO 2020 Theory Exam 1 - General instructions for theoretical examinations

Sep 26, 2026

IBO 2020 Theory Exam 1 provides official examination licensing and usage terms under CC BY-NC-SA 4.0 for non-commercial educational use with attribution and share-alike licensing. The document lists general instructions for theoretical exams, including required answer sheets, identification details, signing requirements, correct equipment, and strict rules on calculators, communication, and outside information access. It also outlines on-site and online supervision procedures for collecting and submitting question and answer sheets, followed by subject questions in biochemistry and cell biology.

LanguageEnglish

CategoryExam

FormatPDF

Pages65

Reading Time2 h 44 min

AccessFree to download

General instructions for theoretical examinations

Exam 1

Instruction and regulations

Biochemistry

Cell Biology

All IBO examination questions are published under the following Creative Commons license: CC BY-NC-SA (Attribution-NonCommercial-ShareAlike) -[https://creativecommons.org/licenses/by-nc-sa/4.0/](https://creativecommons.org/licenses/by-nc-sa/4.0/) The exam papers can be used freely for educational purposes as long as IBO is credited and new creations are licensed under identical terms. No commercial use is allowed. General instructions for theoretical examinations Exam 1 • Date: August 12th 2020 • Total time of Exam 1 is 3 hours. Follow the instruction by Jury members of your country. • Exam 1 consists of 50 questions. • Each correct answer scores 1 marks, each incorrect or missing answer score 0 marks. Instruction and regulations • Make sure that you are using the correct answer sheet (Theoretical exam 1) . • Write your Country code and student ID number (provided by a jury member or supervisor) in the given box of the answer sheets provided, and write down your name. • Make sure to sign all the answer sheets and the cover page of question sheets. • You must mark your answer to the answer sheets properly, using a pen or a pencil. • You must have the following equipment for this exam. ① Pen or pencil to mark answer sheets. ② Scratch paper sheets provided by Jury member. (You must not bring any paper into the examination room by yourself.) ③ Ruler and eraser. • The use of a calculator is prohibited, including a calculator application on your PC or a web browser. • You must not communicate with any other people in the room during the examination. • You must not access any information that could unfairly help you answer the questions during the examination. • Stop answering immediately at the end of examination time. • After the examination: ① If you are under on-site supervision, a jury member / supervisor will collect your question and answer sheets immediately after each exam. Your country coordinator will later scan and submit the sheets to the IBO2020 Organizing Committee. ② If you are under online supervision, you (competitor) must scan (or take photos of) the answer sheets. Then, digitally send the scanned files/photos and the PDF question sheets (with your signature on the cover page) to your country coordinator as soon as possible. Your country coordinator will submit the file to the IBO2020 Organizing Committee. Make sure the answer sheets are scanned correctly. The IBO2020 office may ask you to resubmit the sheet, so don’t discard them. Biochemistry Q1 The citric acid cycle is central to metabolism, for the supply energy and various key compounds. In citric acid cycle, the enzyme aconitase catalyzes the reversible conversion between citrate and isocitrate. In this reaction, OH group at C3 and H group at C4 of citrate are removed as water, thereafter a water molecule is added back in a reverse manner to generate isocitrate (Figure 1) . However, OH group is never added at C2 . aconitase citrate isocitrate Figure 1 Indicate whether each of the following statements is true or false. A. Citrate has enantiomers. 1 B. Isocitrate has enantiomers. 2 C. Two –CH2COO– groups are stereochemically equivalent when citrate is free in solution. 3 D. Two –CH2COO– groups are stereochemically equivalent when citrate is bound to aconitase. 4 Biochemistry Q2 The figure 1 illustrated below shows oxygen consumption (respiration) in aqueous suspension of intact animal mitochondria with additions of ADP or chemical compounds (dinitrophenol (DNP) or N,N'-dicyclohexylcarbodiimide (DCCD)) . The suspension already contains respiratory substrates, oxygen, and inorganic phosphate. Figure 1. Oxygen consumption of mitochondria in suspension. Identical aliquots of ADP were added in both experiments. Indicate whether each of the following statements is true or false. A. The mitochondria are able to incorporate exogenously added ADP. 5 B. Before addition of chemical

FAQs

What license governs the IBO 2020 examination questions?

The questions are published under CC BY-NC-SA (Attribution-NonCommercial-ShareAlike) 4.0.

What items are prohibited during the theoretical exam?

Calculator use is prohibited, including calculator apps on a PC or web browser, and communication with other people in the room is not allowed.

How are answer sheets handled after the exam under on-site versus online supervision?

Under on-site supervision, a jury member/supervisor collects the sheets immediately after each exam. Under online supervision, competitors scan or photograph the sheets and submit the scanned files and the signed question PDF to the country coordinator as soon as possible.

Sep 26, 2026

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