This practice exam (epreuve zero) in Life and Earth Sciences (SVT) from the EEHB Baccalaureate 2022 session is a comprehensive document containing both the exam questions and detailed answer key. Designed as a preparatory examination, it serves as a valuable revision tool for candidates.

Part A begins with knowledge assessment through an Open Response Questions (QRO) exercise on cell biology, particularly osmotic phenomena: comparing vacuolar sap concentrations in plasmolyzed and turgescent plant cells, water movement direction, and characteristics of hypotonic and hypertonic environments. A document analysis exercise addresses molecular biology through hemoglobin electrophoresis result analysis, identifying allelic forms of the beta-globin gene and explaining homozygous and heterozygous profiles.

The practical skills assessment includes a genetics exercise on monohybrid crosses with dominance. Through the study of crested chicken breeding, candidates must analyze phenotypic proportions, perform genotypic interpretation, and discover a special case of a lethal gene in the homozygous dominant state. This exercise engages genetic reasoning and problem-solving skills.

Part B evaluates competencies through a problem-based scenario centered on raising awareness about the role of nervous tissue in body function. The scenario features a young footballer who lost his athletic abilities following drug consumption. Candidates must:

• Write a text explaining how drugs disrupt nervous system function (neurotransmission, membrane receptors, reuptake)
• Design a poster with annotated diagrams illustrating normal and disrupted synapse function
• Create a slogan alerting youth about the role of the nervous system and the need to protect it

The complete answer key is included with detailed evaluation grids comprising criteria for relevance, mastery of scientific knowledge, and coherence. This document is an essential training tool for Baccalaureate series C and Ti candidates wishing to review cell biology, genetics, molecular biology, and neurophysiology.