# JAMB & WAEC Biology: Cell Organization, Ecology, Plant & Animal Nutrition, Transport, Respiration, Excretion, Genetics & Evolution > Covers JAMB UTME & WAEC WASSCE Biology syllabus: Levels of Organization, Cell Organelles, Osmosis/Diffusion, Photosynthesis, Mammalian Dentition & Digestion, Transport, Excretory Organs, Nervous/Endocrine Systems, Nigerian Ecological Biomes, Mendelian Genetics, and Evolution. - **Canonical URL:** https://flashcards.world/flashcards/sets/f74fb730-8c8b-429c-a151-282194083b4b/ - **Markdown URL:** https://flashcards.world/flashcards/sets/f74fb730-8c8b-429c-a151-282194083b4b.md - **Level:** basic - **Languages:** en → en - **Total Cards:** 32 ## Flashcards (32 Cards) | # | Front (Term / Prompt) | Back (Definition / Answer) | Example | Multiple-Choice Options | | :--- | :--- | :--- | :--- | :--- | | 1 | In JAMB/WAEC Ecology (Symbiosis / Biological Associations), distinguish Mutualism, Commensalism, and Parasitism with examples. | Mutualism (+/+): both benefit (lichens = alga + fungus; Rhizobium nitrogen-fixing bacteria in root nodules of legumes; protozoa in termite gut). Commensalism (+/0): one benefits, host unaffected (remora fish on shark; epiphytic fern on palm tree). Parasitism (+/-): parasite benefits at host's expense (dodder/Cassytha or mistletoe on plants; tapeworm/Plasmodium in humans). | | | | 2 | In JAMB/WAEC Ecological Succession, what is the difference between Primary Succession and Secondary Succession? | Primary succession begins on a completely bare, lifeless substrate with no prior soil (e.g., bare rock colonized by pioneer lichens/mosses, or a newly formed sand dune). Secondary succession occurs on a previously colonized habitat where the vegetation was destroyed (by bush fire, farming, or flooding) but soil and seeds/spores already exist, so it reaches a climax community much faster. | | | | 3 | In JAMB/WAEC Nitrogen Cycle, which bacteria perform Nitrogen Fixation, Nitrification (Ammonia -> Nitrite -> Nitrate), and Denitrification? | Nitrogen fixation (N2 -> NH3): Rhizobium (symbiotic in legumes), Azotobacter, Clostridium, and Nostoc (free-living), plus lightning. Nitrification: Nitrosomonas oxidizes ammonium (NH4+) to nitrite (NO2-), and Nitrobacter oxidizes nitrite (NO2-) to nitrate (NO3-). Denitrification (NO3- -> N2 gas in waterlogged soils): Pseudomonas denitrificans. | | | | 4 | In WAEC/JAMB Biology, what is the difference between Plasmolysis and Haemolysis (or Turgidity)? | Plasmolysis is the shrinkage of the protoplasm away from the cell wall of a plant cell placed in a hypertonic solution due to exosmosis. Haemolysis is the bursting of a red blood cell in a hypotonic solution due to endosmosis (plant cells become turgid instead of bursting because of their rigid cellulose cell wall). | | | | 5 | In JAMB/WAEC Plant Hormones & Tropisms, how does Auxin distribution explain positive phototropism in shoots and positive geotropism in roots? | Unilateral light causes auxin to migrate to the shaded side of the shoot tip; higher auxin concentration stimulates cell elongation in shoots, making the shaded side grow faster and bend toward light. In a horizontal root, gravity pulls auxin to the lower side, where high auxin INHIBITS root cell elongation, so the upper side grows faster and the root bends downward. | | | | 6 | In JAMB/WAEC Sex-Linked Inheritance, why are X-linked recessive traits like Haemophilia and Red-Green Colour Blindness much more common in males than in females? | Males are hemizygous (XY) and have only one X chromosome inherited from their mother, so a single recessive allele on the X chromosome expresses the disorder; females (XX) require two recessive alleles to be affected. | | | | 7 | In JAMB/WAEC Human Genetics (Sickle-Cell Anaemia & ABO Blood Groups), if two sickle-cell trait carriers (HbA HbS × HbA HbS) marry, what is the probability of having a child with sickle-cell anaemia (HbS HbS)? | 25% (1/4) probability of HbS HbS (sickler), 50% (1/2) probability of HbA HbS (carrier), and 25% (1/4) probability of HbA HbA (normal). For ABO blood groups, alleles IA and IB are codominant while i (O) is recessive; Group O is the universal donor and Group AB is the universal recipient. | | | | 8 | In JAMB/WAEC Seed Germination, what is the difference between Epigeal and Hypogeal germination, with common West African crop examples? | Epigeal germination: the hypocotyl elongates and carries the cotyledons ABOVE the soil surface (e.g., cowpea/beans, groundnut, mango, castor oil, flamboyant). Hypogeal germination: the epicotyl elongates while the cotyledons remain BELOW the soil surface (e.g., maize, guinea corn, oil palm, yam). | | | | 9 | In JAMB/WAEC Plant Transport, what are the structural and functional differences between Xylem and Phloem tissues, and what did the Ringing (Girdling) Experiment prove? | Xylem consists of dead lignified vessels/tracheids that conduct water and mineral salts upward from roots via transpiration pull. Phloem consists of living sieve tubes and companion cells that translocate manufactured food (sucrose) bidirectionally. Ringing removes the outer phloem ring, causing swelling above the ring and proving that food is translocated downward through the phloem. | | | | 10 | In JAMB/WAEC Genetics, what are Mendel's First Law (Law of Segregation) and Second Law (Law of Independent Assortment), and what is the dihybrid F2 phenotypic ratio? | First Law: paired alleles segregate during gamete formation (meiosis) so each gamete receives only one allele (monohybrid F2 phenotypic ratio 3:1). Second Law: alleles of two different genes assort independently into gametes (dihybrid F2 phenotypic ratio 9:3:3:1). | | | | 11 | In JAMB/WAEC Homeostasis, how does the mammalian skin regulate body temperature during hot weather versus cold weather? | Hot weather: Vasodilation of superficial arterioles (more heat lost by radiation/convection), increased sweating (cooling by evaporation), and relaxation of erector pili muscles (hairs lie flat). Cold weather: Vasoconstriction, cessation of sweating, contraction of erector pili muscles (hairs stand erect to trap insulating air), and shivering. | | | | 12 | In JAMB/WAEC Social Insects, what are the castes in a Termite colony (Isoptera) or Honeybee hive, and what is the specific role of each caste? | In a termite colony: King and Queen (wingless after nuptial flight; sole reproductive function—queen lays thousands of eggs), Soldiers (sterile, large mandibles or nasute snout to defend the termitarium), and Workers (sterile, blind, wingless; build the mound, forage for food, and feed the queen, king, soldiers, and nymphs). | | | | 13 | In JAMB/WAEC Evolution, how does Jean-Baptiste Lamarck's Theory of Inheritance of Acquired Characteristics differ from Charles Darwin's Theory of Natural Selection? | Lamarck argued that organs grow or shrink through use and disuse during an organism's lifetime and these acquired changes are inherited by offspring (disproved by Weismann's mice tail experiment). Darwin argued that natural genetic variations exist within populations, and individuals with advantageous traits survive the struggle for existence ('survival of the fittest') and pass those heritable alleles to offspring. | | | | 14 | In JAMB/WAEC Excretion, match each organism with its specialized excretory structure: Amoeba, Flatworm (Planaria), Earthworm, Insect (Cockroach), Crustacean, Mammal, and Flowering Plant. | Amoeba: Contractile vacuole; Flatworm: Flame cells (protonephridia); Earthworm: Nephridia; Insect: Malpighian tubules (excreting uric acid crystals); Crustacean (prawn): Green glands; Mammal: Kidneys (nephrons); Plant: Stomata and Lenticels. | | | | 15 | In JAMB/WAEC Human Digestion, which enzymes act on carbohydrates, proteins, and lipids in the mouth, stomach, and duodenum, and what is the role of bile? | Mouth: Salivary amylase (ptyalin) converts cooked starch to maltose. Stomach: Pepsin converts proteins to peptones/polypeptides; Rennin coagulates milk protein (caseinogen to casein). Duodenum (Pancreatic juice): Amylase (starch -> maltose), Trypsin (peptones -> peptides), Lipase (fats -> fatty acids + glycerol). Bile (produced by liver, stored in gallbladder) contains no enzymes; it emulsifies fats and neutralizes acidic chyme. | | | | 16 | In JAMB/WAEC Endocrine System, which hormone is known as the 'fight or flight' emergency hormone, which regulates basal metabolic rate (requiring iodine), and which regulates blood glucose? | Adrenaline (epinephrine) from the adrenal medulla is the emergency hormone; Thyroxine from the thyroid gland regulates basal metabolic rate (deficiency causes goitre or cretinism in children); Insulin (beta cells of Islets of Langerhans) lowers blood glucose by converting glucose to glycogen, while Glucagon (alpha cells) raises blood glucose. | | | | 17 | In JAMB/WAEC Skeletal System, what are the distinct features of the Atlas, Axis, Cervical, Thoracic, and Lumbar vertebrae in mammals? | Atlas (1st cervical): large neural canal, no centrum, articulatory facets for nodding. Axis (2nd cervical): peg-like odontoid process for head rotation. Cervical (neck): possesses vertebro-arterial canals in transverse processes. Thoracic (chest): long backward-pointing neural spine for rib attachment. Lumbar (lower back): thick massive centrum and long transverse processes for abdominal support. | | | | 18 | In JAMB/WAEC Plant Nutrition, what happens during the Light-Dependent Stage vs. Light-Independent (Dark / Calvin Cycle) Stage of Photosynthesis, and where does each occur? | Light stage (in the grana/thylakoids of chloroplasts): chlorophyll traps light energy for photolysis of water (2H2O -> 4H+ + O2) and produces ATP and NADPH. Dark stage (in the stroma): CO2 is reduced by hydrogen ions (via RuBisCO) to form glucose. | | | | 19 | In WAEC/JAMB Mineral Nutrition of Plants, what deficiency symptoms are caused by a lack of Nitrogen, Magnesium, and Iron in plants? | Nitrogen, Magnesium, and Iron are all required for chlorophyll synthesis (Magnesium is the central atom of chlorophyll); deficiency causes chlorosis (yellowing of leaves) and stunted growth. | | | | 20 | In WAEC/JAMB Cell Biology, what are the specific functions of the Mitochondrion, Ribosome, Golgi apparatus, Lysosome, and Endoplasmic Reticulum? | Mitochondrion: site of aerobic cellular respiration (ATP production); Ribosome: protein synthesis; Golgi apparatus: packaging, modification, and secretion of glycoproteins; Lysosome: intracellular digestion and autolysis ('suicide bag'); Rough ER: protein transport; Smooth ER: lipid/steroid synthesis and detoxification. | | | | 21 | In JAMB/WAEC Nephron Physiology, where do Ultrafiltration and Selective Reabsorption take place in the mammalian kidney? | Ultrafiltration takes place in the glomerulus and Bowman's capsule (driven by high hydrostatic pressure). Selective reabsorption of glucose, amino acids, and water occurs in the Proximal Convoluted Tubule (PCT), while the Loop of Henle and Distal Convoluted Tubule/Collecting Duct regulate water and salt balance under ADH and Aldosterone. | | | | 22 | In JAMB/WAEC Nervous System, what are the functions of the Cerebrum, Cerebellum, and Medulla Oblongata of the mammalian brain? | Cerebrum (forebrain): voluntary actions, intelligence, memory, reasoning, and sensory perception. Cerebellum (hindbrain): muscular coordination, posture, and body balance. Medulla Oblongata (hindbrain): involuntary vital reflexes (heartbeat, breathing, blood pressure, swallowing, coughing). | | | | 23 | In JAMB/WAEC Variation, classify human traits into Continuous (Morphological) Variation versus Discontinuous (Physiological) Variation. | Continuous variation (shows a normal bell curve from extremes, influenced by polygenes and environment): height, body weight, skin colour, intelligence, fingerprint ridge count. Discontinuous variation (distinct categories with no intermediates, controlled by single genes): ABO blood group, ability to roll the tongue, ability to taste PTC, sex, fingerprint pattern type. | | | | 24 | In JAMB/WAEC Nigerian Local Biomes, what are the vegetation belts of Nigeria in order from the Atlantic coast (South) to the far North, and their characteristic trees/grasses? | 1. Mangrove Swamp Forest (red/white mangroves with breathing pneumatophores and stilt roots), 2. Tropical Rainforest (tall stratified trees with buttress roots, epiphytes—iroko, mahogany, obeche, oil palm), 3. Guinea Savanna (largest biome in Nigeria; tall grasses and fire-resistant trees with thick bark—isoberlinia, shea butter, locust bean), 4. Sudan Savanna (shorter grasses, acacia, baobab), 5. Sahel Savanna (Around Lake Chad; thorny shrubs, drought-resistant xerophytes). | | | | 25 | Why is Euglena viridis classified as having both plant and animal characteristics in WAEC/JAMB Biology? | Plant characteristics: possesses chloroplasts for photosynthesis, pyrenoids for starch (paramylum) storage, and holophytic nutrition in light. Animal characteristics: possesses a pellicle instead of a cellulose cell wall, a gullet, a contractile vacuole, an eyespot (stigma), flagellum for locomotion, and holozoic nutrition in darkness. | | | | 26 | In JAMB/WAEC Ecology, what ecological instruments are used to measure Wind Speed, Wind Direction, Relative Humidity, Water Turbidity, and Soil/Air Pressure? | Anemometer (wind speed); Wind vane (wind direction); Hygrometer / Wet-and-Dry Bulb Thermometer (relative humidity); Secchi disc (turbidity/transparency of water); Barometer (atmospheric pressure). | | | | 27 | In JAMB/WAEC Mammalian Circulation, why is mammalian circulation described as 'closed and double circulation', and why is the left ventricle wall thicker than the right ventricle? | Blood remains inside vessels (closed) and passes through the heart twice per complete circuit: Pulmonary circulation (right ventricle -> lungs -> left atrium) and Systemic circulation (left ventricle -> body tissues -> right atrium). The left ventricle has a much thicker muscular wall (myocardium) to generate high pressure to pump blood throughout the entire systemic body. | | | | 28 | In JAMB & WAEC Biology, what are the four levels of organization of life with classic examples tested in past questions? | 1. Cell (Amoeba, Paramecium, Euglena, Chlamydomonas, Red blood cell), 2. Tissue (Hydra, muscle, xylem/phloem, epidermis), 3. Organ (Onion bulb, rhizome, heart, kidney, leaf, flower), 4. Organ System (Circulatory system, shoot system). | | | | 29 | In JAMB/WAEC Mammalian Dentition, what is the dental formula of an adult human vs. a herbivore (rabbit) vs. a carnivore (dog)? | Adult human (32 teeth): I 2/2, C 1/1, PM 2/2, M 3/3. Rabbit (28 teeth, lacks canines—has a gap called the diastema): I 2/1, C 0/0, PM 3/2, M 3/3. Dog (42 teeth, has carnassial teeth—upper last premolar & lower first molar): I 3/3, C 1/1, PM 4/4, M 2/3. | | | | 30 | In JAMB/WAEC Plant Reproduction, what is Double Fertilization in angiosperms (flowering plants), and what do the ovule and ovary develop into after fertilization? | One male gamete fuses with the egg cell (ovum) to form a diploid zygote (2n -> embryo), while the second male gamete fuses with the two polar nuclei (definitive nucleus) to form the triploid endosperm nucleus (3n -> nutritive endosperm). After fertilization, the fertilized ovule becomes the SEED and the ovary becomes the FRUIT. | | | | 31 | In WAEC Practical Biology (Food Tests), which reagents test for Starch, Reducing Sugars, Non-Reducing Sugars, Proteins, and Fats/Oils, and what are the positive color changes? | Starch: Iodine solution -> Blue-black. Reducing sugar (glucose): Fehling's A+B or Benedict's solution + heat -> Brick-red precipitate. Protein: Biuret test (NaOH + CuSO4) -> Purple/violet; Millon's reagent + heat -> Brick-red precipitate. Fats/Oils: Sudan III -> Red layer, or translucent grease spot on filter paper. | | | | 32 | In JAMB/WAEC Sense Organs (Mammalian Eye), how does the eye adjust (accommodate) to view a NEAR object versus a DISTANT object, and how are Myopia and Hypermetropia corrected? | Near object: Ciliary muscles CONTRACT, suspensory ligaments slacken, and the lens becomes thicker/more convex (shorter focal length). Distant object: Ciliary muscles RELAX, suspensory ligaments pull taut, lens becomes thin/flat. Myopia (short-sightedness—image forms in front of retina): corrected with a concave (diverging) lens. Hypermetropia (long-sightedness—image behind retina): corrected with a convex (converging) lens. | | | --- Study this deck interactively with FSRS-6 spaced repetition, audio review, and multiple-choice mode at [Flashcards World](https://flashcards.world/flashcards/sets/f74fb730-8c8b-429c-a151-282194083b4b/).