Lebanese Baccalaureate - Life Sciences (LS) study guide
Lebanese Baccalaureate - Life Sciences (LS) · Work through your exam, one topic at a time.
The Lebanese Baccalaureate in Life Sciences (Bac LS, Sciences de la Vie) is the national school-leaving credential awarded to secondary students in Lebanon who follow the life-sciences track. It matters chiefly as a gateway: strong results support admission to university programs in medicine, pharmacy, biology, agronomy, and paramedical fields, in Lebanon and abroad. The Lebanese Baccalaureate - Life Sciences (LS) study guide has 9 sections and about 2,169 words.
01Cell Biology and Cellular Physiology
A candidate must be able to describe the plasma membrane as a fluid mosaic (phospholipid bilayer, integral and peripheral proteins, cholesterol, glycoproteins) and explain each transport mode: simple diffusion, facilitated diffusion, osmosis, primary active transport (Na⁺/K⁺ ATPase), and vesicular transport (endocytosis, exocytosis). Know the organelles and their functions - nucleus, mitochondria, rough and smooth ER, Golgi apparatus, lysosomes, ribosomes, cytoskeleton - and the difference between prokaryotic and eukaryotic organization.
329 words, about 2 min02Genetics and Molecular Biology
Master DNA structure (double helix, antiparallel strands, complementary base pairing A–T, G–C), semi-conservative replication, transcription, and translation (codons, anticodons, ribosomes, start/stop codons). Know the genetic code is degenerate and non-overlapping.
281 words, about 1 min03Human Physiology and Homeostasis
Understand negative feedback as the organizing principle of homeostasis (thermoregulation, blood glucose, water/salt balance, blood pH). Know the composition and functions of blood, the cardiac cycle, blood pressure regulation, gas exchange in alveoli, and the nephron's role in filtration, reabsorption, and secretion.
259 words, about 1 min04Nervous System and Sensory Organs
Know neuron structure, resting potential (Na⁺/K⁺ pump, K⁺ leak), action potential phases (depolarization by Na⁺ influx, repolarization by K⁺ efflux, refractory period), and synaptic transmission (neurotransmitters, excitatory vs. inhibitory synapses).
235 words, about 1 min05Endocrine Regulation and Reproduction
Understand hormones as chemical messengers acting on target cells via receptors; distinguish steroid (intracellular receptors, gene expression) from peptide/protein hormones (membrane receptors, second messengers). Know the hypothalamic–pituitary axis and feedback loops for thyroid, adrenal, and gonadal hormones.
230 words, about 1 min06Immunology and Defense Mechanisms
Distinguish innate (non-specific: skin, mucus, phagocytes, inflammation, complement) from adaptive immunity (specific: B and T lymphocytes, antibodies, memory). Know humoral immunity (B cells → plasma cells → antibodies) and cell-mediated immunity (T cells, cytotoxic T cells killing infected cells, helper T cells coordinating).
229 words, about 1 min07Ecology and Environmental Science
Understand levels of organization (organism, population, community, ecosystem, biosphere) and the factors that regulate populations (biotic potential, carrying capacity, density-dependent vs. density-independent factors).
201 words, about 1 min08Evolution and Biodiversity
Understand natural selection (variation, heritability, differential reproduction), adaptation, and evidence for evolution (fossils, comparative anatomy, molecular data). Know mechanisms of change: mutation, gene flow, genetic drift, natural selection.
192 words, under 1 min09Scientific Method, Experimental Analysis, and Data Interpretation
Know the steps of the scientific method: observation, hypothesis, prediction, experiment, data analysis, conclusion. Distinguish independent, dependent, and controlled variables; understand control groups, replication, and sample size.
213 words, about 1 min