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Key Facts: Guinea Bac Sciences Expérimentales Exam

Coefficient 4

Biologie-Géologie Paper Weighting, 4-Hour Duration (Série SE)

Guinea Baccalauréat SE Biologie-Géologie paper header, 2020 session

10.00 / 20

Minimum General Average to Pass

DGECS-CP 2026 rattrapage communiqué

8.50 – 9.99

Average Range Eligible for the New Rattrapage Session

Ministry communiqué of 29 June 2026

7 Papers

Written Papers Sat by the Sciences Expérimentales Série

DGECS-CP 2026 examination timetable, published 18 May 2026

The Guinea Baccalauréat Sciences Expérimentales is the premier life and natural sciences secondary exit exam administered by DGECS-CP, qualifying students for medicine, pharmacy, and STEM higher education.

Sample Guinea Bac Sciences Expérimentales Practice Questions

Try these sample questions to review concepts for the Guinea Bac Sciences Expérimentales exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In molecular biology, which enzyme is responsible for synthesizing a complementary messenger RNA (mRNA) strand from a DNA template during transcription in the cell nucleus?
A.DNA ligase
B.RNA polymerase
C.Reverse transcriptase
D.DNA helicase
Explanation: RNA polymerase binds to the promoter region of DNA, uncoils the double helix, and synthesizes a complementary pre-mRNA molecule in the 5' to 3' direction using ribonucleotides.
2In human genetics, hemophilia A is an X-linked recessive disorder. If a carrier female (X^H X^h) has children with an unaffected male (X^H Y), what is the probability that a son born to this couple will be affected with hemophilia?
A.0%
B.25%
C.50%
D.100%
Explanation: A son inherits the Y chromosome from his father and one X chromosome from his mother. The mother has genotype X^H X^h. There is a 50% chance the son inherits X^h (affected X^h Y) and a 50% chance he inherits X^H (normal X^H Y).
3What phenotypic segregation ratio is observed in the F2 generation of a Mendelian dihybrid cross involving two unlinked, independently assorting genes with complete dominance (e.g., crossing F1 heterozygous AaBb × AaBb)?
A.3 : 1
B.9 : 3 : 3 : 1
C.1 : 2 : 1
D.1 : 1 : 1 : 1
Explanation: Mendel's Law of Independent Assortment produces four distinct phenotypic classes in a dihybrid cross with complete dominance in the classic 9/16 [AB], 3/16 [Ab], 3/16 [aB], 1/16 [ab] ratio.
4Which specialized immune cells differentiate from activated B-lymphocytes and actively secrete large quantities of specific antibodies into bodily fluids?
A.Cytotoxic CD8+ T-lymphocytes
B.Plasma cells (plasmocytes)
C.Natural killer (NK) cells
D.Basophil granulocytes
Explanation: Upon antigen recognition and helper T-cell activation, B-lymphocytes proliferate and differentiate into memory B cells and plasma cells (plasmocytes), which are antibody-secreting factories.
5What is the primary ionic mechanism responsible for the rapid depolarization phase of a neuronal action potential?
A.Massive influx of Na⁺ ions through voltage-gated sodium channels into the axon
B.Efflux of K⁺ ions through voltage-gated potassium channels
C.Active transport of Ca²⁺ ions by ATPase pumps
D.Influx of Cl⁻ ions through GABA receptors
Explanation: When the threshold potential (~ -55 mV) is reached, voltage-gated Na⁺ channels open rapidly, allowing an influx of Na⁺ driven by chemical and electrical gradients, swinging the membrane potential up to ~ +30 mV.
6Which pituitary gonadotropin hormone triggers the rupture of the mature Graafian follicle and ovulation on approximately day 14 of a standard 28-day human ovarian cycle?
A.Progesterone
B.Human chorionic gonadotropin (hCG)
C.Luteinizing hormone (LH surge / pic de LH)
D.Prolactin
Explanation: A sharp mid-cycle surge in Luteinizing Hormone (LH) secreted by the anterior pituitary gland triggers final follicular maturation, follicle rupture, and the release of the oocyte (ovulation).
7In plate tectonics, what geological phenomenon occurs at a convergent boundary where a dense oceanic lithospheric plate plunges beneath a less dense continental plate?
A.Seafloor spreading at a mid-ocean ridge
B.Subduction, associated with an oceanic trench, volcanic arc, and deep Wadati-Benioff seismic zone
C.Transform fault sliding without crustal destruction
D.Continental rifting forming a graben
Explanation: Subduction occurs when a dense oceanic lithosphere descends into the asthenosphere beneath a continental or lighter oceanic plate, creating a deep marine trench, intense Wadati-Benioff seismicity, and calc-alkaline volcanism.
8How are the vast Guinean bauxite deposits (such as those in Boké, Kindia, and Fria) geologically formed?
A.By deep subterranean volcanic magma crystallization
B.Through intense tropical weathering (lateritization / altération météorique) of aluminosilicate-rich rocks under hot, humid climates with contrasting seasons
C.By sedimentation in ancient deep marine abyssal plains
D.Through glacial erosion and moraine deposition
Explanation: Bauxite in Guinea is a residual lateritic ore formed by prolonged chemical weathering of aluminosilicate parent rocks under alternating humid and dry tropical climates, leaching soluble silica and bases (ferralitization) and concentrating insoluble aluminum hydroxides (gibbsite, boehmite).
9During cellular aerobic respiration, what is the net yield of ATP molecules generated per molecule of glucose by substrate-level phosphorylation during cytoplasmic glycolysis?
A.2 net ATP molecules
B.4 net ATP molecules
C.32 net ATP molecules
D.38 net ATP molecules
Explanation: Glycolysis consumes 2 ATP in its preparatory phase and produces 4 ATP in its payoff phase, resulting in a net gain of 2 ATP per glucose molecule along with 2 NADH and 2 pyruvate.
10What is the function of the myelin sheath produced by Schwann cells around peripheral axons?
A.It stores calcium ions for muscle contraction
B.It electrically insulates the axon, enabling rapid saltatory conduction of nerve impulses from node to node
C.It synthesizes hemoglobin for oxygen transport
D.It secretes digestive pepsin
Explanation: The myelin sheath is a lipid-rich insulating layer interrupted at nodes of Ranvier. Action potentials jump from one node of Ranvier to the next (saltatory conduction), accelerating nerve conduction up to 100-fold.

About the Guinea Bac Sciences Expérimentales Exam

The Baccalauréat Unique — Série Sciences Expérimentales (SE) is the premier national secondary school exit credential in the Republic of Guinea for students completing senior secondary education in the life, chemical, and physical sciences track. Administered annually by the Direction Générale des Examens et Contrôle Scolaire (DGECS) under the Ministry of National Education, Literacy, Technical Education and Vocational Training (which absorbed the former MEPU-A in January 2026), the Baccalauréat Unique certifies secondary graduation and serves as the competitive admission passport to faculties of medicine, pharmacy, dentistry, agronomy, environmental sciences, biochemistry, and polytechnics. The curriculum centers on deep biological knowledge — molecular genetics, human immunology, neurophysiology, reproductive biology, and Guinean ecology — paired with rigorous general and organic chemistry, classical and modern physics, calculus, and philosophy. Format and language note: the official examination is written in French and assessed through extensive experimental data interpretation, chemical balance equations, physics calculations, and philosophical essays, not multiple-choice questions. This site's practice bank is a 100-question English-language MCQ study adaptation of the official syllabus — a study aid for the underlying scientific principles. It is not an official translation, not an official-format simulation, and not a substitute for practicing French-language written problem solving.

Exam sponsor: Direction Générale des Examens et Contrôle Scolaire (DGECS). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

National secondary school exit examination organised annually by the DGECS-CP at the end of Terminale. The série Sciences Expérimentales (SE) sits seven written papers: Biologie-Géologie, Chimie, Physique, Mathématiques, Français, Anglais and Philosophie. Papers carry published coefficients — the 2020 SE Biologie-Géologie paper was headed 'Coefficient : 4, Durée : 4 heures' and the SE Physique paper 'Coefficient : 3, Durée : 3 heures' — and each is marked out of 20. From the 2026 session, candidates finishing the ordinary session with an average between 8.50 and 9.99 out of 20 may sit a rattrapage in at most two subjects, with priority to the specialty subjects; a resit mark replaces the ordinary mark only when it is higher, and a final average of at least 10.00/20 carries the same diploma.

Time Limit

Four written-paper days inside a five-day window; the 2026 ordinary session ran Monday 29 June to Friday 3 July 2026 with a rest day on Wednesday 1 July. The 2026 rattrapage session ran 20–23 August 2026.

Passing Score

Moyenne générale of at least 10.00/20 across the weighted papers

Exam / Certification Fees

Not published by DGECS-CP; registration is handled through the ministry platform www.dgecs.com and no examination fee is stated on the official notices

Exam sponsor website

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

36%

Biologie-Géologie

Transcription and the genetic code, Mendelian and sex-linked inheritance, karyotype anomalies, immunity (plasma cells, MHC-I, memory, autoimmunity), neurophysiology (action potential, myelin, synapse, stretch reflex), endocrine regulation of glycaemia and the ovarian cycle, circulation and baroreflex, excretion, cell biology, bioenergetics, ecology of Guinea (Nimba, Ziama, mangroves, bowé), plate tectonics, metamorphism, seismology and lateritic bauxite.

16%

Chimie

Strong-base pH, weak acid–base couples and half-equivalence, buffer chemistry, oxidation numbers, lead-acid accumulators, solubility products, mild oxidation of alcohols, Tollens' test, amino acids and the zwitterion, peptide bonds, saponification value, polymerisation, stereochemistry and catalytic cracking.

14%

Physique

RC circuits and the time constant, capacitor energy, spring oscillators, Newton's law of cooling, electromagnetic induction and alternators, total internal reflection in optical fibres, the electromagnetic spectrum and medical imaging, acoustics, mass defect, beta decay, carbon-14 dating and D-T fusion.

12%

Mathématiques

Derivatives of logarithmic, exponential, rational and product functions, exponential equations, integration by parts and definite integrals, exponential growth and decay models, conditional probability, and descriptive statistics and linear correlation.

8%

Philosophie

Vitalism and mechanism, the experimental method (Claude Bernard), Bachelard's epistemological obstacle, Kant on natural purposes, Lévi-Strauss on nature and culture, bioethics (informed consent, germline editing) and Hans Jonas on responsibility.

7%

Français

Francophone African literature (Mongo Beti, Ferdinand Oyono, Négritude), the dialectical dissertation and its synthesis, and figures of speech.

7%

Anglais

Scientific and medical vocabulary, the mandative subjunctive, passive and conditional structures, and laboratory terminology.

Preparing for the Guinea Bac Sciences Expérimentales Exam

What You Need to Know

  • Passing score: Moyenne générale of at least 10.00/20 across the weighted papers
  • Assessment: National secondary school exit examination organised annually by the DGECS-CP at the end of Terminale. The série Sciences Expérimentales (SE) sits seven written papers: Biologie-Géologie, Chimie, Physique, Mathématiques, Français, Anglais and Philosophie. Papers carry published coefficients — the 2020 SE Biologie-Géologie paper was headed 'Coefficient : 4, Durée : 4 heures' and the SE Physique paper 'Coefficient : 3, Durée : 3 heures' — and each is marked out of 20. From the 2026 session, candidates finishing the ordinary session with an average between 8.50 and 9.99 out of 20 may sit a rattrapage in at most two subjects, with priority to the specialty subjects; a resit mark replaces the ordinary mark only when it is higher, and a final average of at least 10.00/20 carries the same diploma.
  • Time limit: Four written-paper days inside a five-day window; the 2026 ordinary session ran Monday 29 June to Friday 3 July 2026 with a rest day on Wednesday 1 July. The 2026 rattrapage session ran 20–23 August 2026.
  • Exam / certification fees: Not published by DGECS-CP; registration is handled through the ministry platform www.dgecs.com and no examination fee is stated on the official notices Official sources

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Frequently Asked Questions

What is the Guinea Baccalauréat Sciences Expérimentales examination?

The Baccalauréat Unique — Série Sciences Expérimentales (SE) is the official national secondary school exit credential in Guinea for students in the life and natural sciences track. It is the primary credential required for admission into faculties of medicine, pharmacy, biomedical sciences, agronomy, and biology.

What subjects are tested on the Baccalauréat Sciences Expérimentales?

The série Sciences Expérimentales sits seven written papers: Biologie-Géologie, Chimie, Physique, Mathématiques, Français, Anglais and Philosophie. Each is marked out of 20 and carries a coefficient printed on the paper — the 2020 SE Biologie-Géologie paper was headed 'Coefficient : 4, Durée : 4 heures' and the SE Physique paper 'Coefficient : 3, Durée : 3 heures'. DGECS-CP does not publish a consolidated coefficient table, so treat any full table quoted elsewhere as unverified.

What passing average is required on the Baccalauréat in Guinea?

Candidates must achieve a cumulative weighted general average (moyenne générale) of at least 10.00 out of 20 (≥ 10/20) across all written papers to obtain the Baccalauréat Unique diploma.

How does Sciences Expérimentales differ from Sciences Mathématiques?

Sciences Expérimentales focuses intensely on biological sciences, cellular biology, genetics, immunology, and chemistry, with applied calculus. Sciences Mathématiques focuses on advanced pure mathematics (complex numbers, 3D geometry, analysis) and theoretical physics.

Is there a resit session if I just miss the pass mark?

Yes, since the 2026 session. A ministry communiqué of 29 June 2026 created a rattrapage for candidates whose ordinary-session average falls between 8.50 and 9.99 out of 20. Candidates resit at most two subjects, with priority given to the specialty subjects, and a resit mark replaces the ordinary mark only when it is higher. A final average of at least 10.00/20 carries a diploma of identical academic and legal value. The first rattrapage ran 20–23 August 2026, with results on 2 September 2026.