100+ Free Cameroon GCE A-Level Biology Practice Questions

cell-biology-biochemistry

Microscopy and magnification calculations; prokaryotic and eukaryotic organelle ultrastructure (nucleus, mitochondria, chloroplasts, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, centrioles); plasma membrane fluid mosaic model and transport mechanisms (simple diffusion, facilitated diffusion, osmosis, active transport, endocytosis); dipolar properties of water and water potential; structure and chemical properties of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids); protein folding levels and stabilizing bonds; enzyme kinetics, Michaelis-Menten constant (Km), Vmax, allosteric regulation, and competitive versus non-competitive inhibition.

bioenergetics

Cellular respiration pathways: glycolysis, link reaction, Krebs citric acid cycle, electron transport chain, chemiosmosis and oxidative phosphorylation; theoretical and actual ATP yields; anaerobic respiration (lactate fermentation in animals and alcoholic fermentation in yeast); Respiratory Quotient (RQ) calculations for carbohydrates, lipids, and proteins; light-dependent photosynthetic reactions: photolysis of water, cyclic and non-cyclic photophosphorylation, Z-scheme; Calvin cycle carbon fixation, RuBisCO carboxylase and oxygenase activities, photorespiration; C3, C4 (Kranz anatomy), and CAM metabolic adaptations; and Blackman's principle of limiting factors.

genetics-evolution

DNA semi-conservative replication mechanism (Meselson-Stahl experiment) and replication fork enzymes; transcription and post-transcriptional pre-mRNA processing (capping, polyadenylation, splicing); universal and degenerate triplet genetic code; translation stages on 70S/80S ribosomes; prokaryotic gene regulation in the lac operon; gene mutations (sickle cell anaemia point mutation) and chromosomal aberrations (nondisjunction and Down syndrome); Mendelian genetics (monohybrid, dihybrid crosses, codominance, sex linkage, epistasis); recombinant DNA technology (restriction enzymes, ligases, plasmids, cDNA synthesis); PCR thermal cycles; gel electrophoresis; natural selection modes (stabilizing, directional, disruptive); speciation mechanisms (allopatric and sympatric speciation); and Hardy-Weinberg equilibrium quantitative calculations.

plant-animal-physiology

Plant transport systems: xylem tracheids and vessels, cohesion-tension theory of transpiration, stomatal opening/closing mechanisms, phloem sieve tubes and companion cells, Münch pressure-flow mass translocation; plant growth regulators (auxin and phototropism, abscisic acid, gibberellins); nervous coordination: resting membrane potential (-70 mV), Na+/K+ pump, action potential generation and propagation, saltatory conduction in myelinated axons, refractory period; chemical synaptic transmission at cholinergic synapses; sliding filament theory of skeletal muscle contraction and calcium signaling; mammalian homeostatic mechanisms: negative feedback, thermoregulation by the hypothalamus, blood glucose control by islet alpha and beta cells; kidney nephron ultrastructure, net ultrafiltration pressure calculations, countercurrent multiplier in the loop of Henle, ADH and aldosterone osmoregulation; cardiac cycle hemodynamics, cardiac output calculations; oxygen-haemoglobin dissociation curves and Bohr effect; and innate versus adaptive humoral (B cell/antibody) and cell-mediated (CD8+ T cell) immunity.

ecology-applied-biology

Ecosystem energetics: trophic levels, ecological pyramids, gross and net primary productivity (NPP = GPP - R calculations); biogeochemical cycles (nitrogen cycle bacteria: Nitrosomonas, Nitrobacter, Rhizobium, Pseudomonas; carbon cycle); population ecology: logistic growth, carrying capacity (K), density-dependent factors, Lincoln-Petersen mark-release-recapture index calculations; ecological succession (primary volcanic lava succession vs secondary succession, pioneer species); tropical infectious diseases and vector epidemiology: malaria (Plasmodium falciparum and Anopheles vector), African sleeping sickness (Trypanosoma brucei and Glossina vector), urinary schistosomiasis (Schistosoma haematobium and Bulinus snail host), cholera (Vibrio cholerae enterotoxin), and HIV-1 viral pathogenesis; environmental toxicology: biomagnification of persistent organochlorines, cultural eutrophication sequence; biodiversity hotspot criteria (endemic plant richness and habitat loss); ex-situ versus in-situ conservation; and modern malaria vaccine immunoprophylaxis (RTS,S / R21).