General Science One Liners for Competitive Exams 2026

Everyday Science one liner - Biology

1. Human Nutrition and Digestion

• What is the chemical name of fat-soluble Vitamin A? - Retinol
• Which eye condition characterized by poor vision in dim light is caused by Vitamin A deficiency? - Night Blindness (Nyctalopia)
• What is the severe drying and ulceration of the cornea caused by Vitamin A deficiency called? - Xerophthalmia
• What is the chemical name of Vitamin B1? - Thiamine
• Which neurological and cardiovascular disorder is caused by a deficiency of Vitamin B1? - Beriberi
• What is the chemical name of Vitamin B2? - Riboflavin
• Which condition causing painful cracking at the corners of the mouth is linked to Vitamin B2 deficiency? - Cheilosis (Angular Cheilitis)
• What is the chemical name of Vitamin B3? - Niacin (Nicotinic Acid)
• Which deficiency disease characterized by diarrhea, dermatitis, and dementia is caused by lack of Vitamin B3? - Pellagra
• What is the chemical name of Vitamin B5? - Pantothenic Acid
• What is the chemical name of Vitamin B6? - Pyridoxine
• What is the chemical name of Vitamin B7? - Biotin
• What is the chemical name of Vitamin B9, essential for fetal neural tube closure? - Folic Acid (Folate)
• What is the chemical name of Vitamin B12, containing the central metal ion cobalt? - Cyanocobalamin
• Which severe hematological disorder results from a lack of Vitamin B12 or intrinsic factor? - Pernicious Anemia
• What is the chemical name of water-soluble Vitamin C? - Ascorbic Acid
• Which nutritional disorder characterized by bleeding gums and delayed wound healing is caused by Vitamin C deficiency? - Scurvy
• Why is Vitamin C easily lost during open boiling or overcooking of food? - It is heat-labile (thermolabile)
• What is the chemical name of Vitamin D3? - Cholecalciferol
• Which disease causing soft, bowed bones in children is caused by a lack of Vitamin D? - Rickets
• What is the adult form of bone softening caused by severe Vitamin D and calcium deficiency called? - Osteomalacia
• What is the chemical name of Vitamin E, which acts as a major lipid-soluble antioxidant? - Tocopherol
• Which vitamin deficiency is associated with reduced fertility and increased RBC fragility? - Vitamin E
• What is the chemical name of Vitamin K1, essential for synthesizing clotting factors? - Phylloquinone
• Which clinical issue occurs when a patient suffers from severe Vitamin K deficiency? - Defective Blood Clotting (Hemorrhage)
• Which four vitamins are classified as fat-soluble? - Vitamins A, D, E, and K
• Which vitamins are classified as water-soluble? - Vitamin B-Complex and Vitamin C
• What is the primary carbohydrate storage form in the human liver and muscles? - Glycogen
• What digestive enzyme present in human saliva hydrolyzes dietary starch into maltose? - Salivary Amylase (Ptyalin)
• What simple monosaccharide serves as the immediate primary respiratory fuel for human cells? - Glucose
• What are the fundamental structural monomers that link via peptide bonds to form proteins? - Amino Acids
• How many standard amino acids are utilized by the human body to synthesize proteins? - 20
• Which severe childhood protein deficiency is characterized by abdominal edema and a potbelly? - Kwashiorkor
• Which wasting disorder is caused by a simultaneous severe deficiency of both protein and total calories? - Marasmus
• What digestive enzyme in gastric juice initiates the breakdown of proteins into peptones in an acidic medium? - Pepsin
• What milk-coagulating enzyme is found in infant gastric juice to digest casein protein? - Rennin (Chymosin)
• How much metabolic energy is yielded by the complete oxidation of 1 gram of dietary fat? - Approximately 9 kcal/g
• What are fats biochemically broken down into during complete intestinal digestion? - Fatty Acids and Glycerol
• What fluid produced by the liver and stored in the gallbladder emulsifies large fat globules? - Bile
• Which pancreatic enzyme hydrolyzes emulsified fats into fatty acids and monoglycerides? - Pancreatic Lipase (Steapsin)
• What essential mineral forms the central oxygen-binding core of blood hemoglobin? - Iron (Fe)
• What nutritional condition is caused by a chronic deficiency of dietary iron? - Microcytic Nutritional Anemia
• Which mineral is required by the thyroid gland to synthesize thyroxine ($\text{T}_4$)? - Iodine (I)
• What is the abnormal enlargement of the thyroid gland due to dietary iodine deficiency called? - Simple Goitre
• Which two minerals constitute the primary structural matrix of human bones and tooth enamel? - Calcium (Ca) and Phosphorus (P)
• What is the hardest substance in the human body that coats the crown of teeth? - Tooth Enamel (Hydroxyapatite)
• Which trace mineral prevents tooth decay at optimal levels but causes fluorosis in excess? - Fluorine (Fluoride)
• What microscopic finger-like projections in the small intestine maximize surface area for nutrient absorption? - Villi and Microvilli
• In which organ of the human digestive tract does the vast majority of chemical digestion and nutrient absorption occur? - Small Intestine (Ileum/Jejunum)
• In which segment of the large intestine are water and electrolytes primarily reabsorbed? - Colon

2. Human Organ Systems: Circulatory and Respiratory Systems

• Who discovered the ABO human blood group system in 1900? - Karl Landsteiner
• Which blood group is known as the 'Universal Donor' because its RBCs lack A and B antigens? - Blood Group O-negative ($\text{O}^-$)
• Which blood group is known as the 'Universal Recipient' because its plasma lacks Anti-A and Anti-B antibodies? - Blood Group AB-positive ($\text{AB}^+$)
• What antigen on red blood cells determines whether a person is Rh-positive or Rh-negative? - Rhesus (Rh) Factor / D Antigen
• What life-threatening hemolytic condition occurs in an Rh-positive fetus carried by an Rh-negative mother? - Erythroblastosis Fetalis
• How many chambers make up the internal anatomy of the human heart? - Four (Two Atria and Two Ventricles)
• What specialized neuromuscular tissue serves as the primary natural pacemaker of the human heart? - Sinoatrial (SA) Node
• Where is the SA node anatomically located in the human heart? - Upper wall of the Right Atrium
• What are the oxygen-carrying, biconcave, enucleated blood cells called? - Erythrocytes (Red Blood Cells - RBCs)
• What is the average lifespan of a human red blood cell circulating in peripheral blood? - 120 Days
• Where are erythrocytes continuously produced in an adult human? - Red Bone Marrow
• Which lymphoid organ is designated as the 'Graveyard of RBCs'? - Spleen
• What are the nucleated blood cells responsible for immune defense against pathogens called? - Leukocytes (White Blood Cells - WBCs)
• Which type of white blood cell is the most numerous in normal human circulation? - Neutrophils (60–65%)
• Which white blood cells are primarily responsible for producing humoral antibodies? - B-Lymphocytes (Plasma Cells)
• What enucleated cell fragments are essential for initiating blood coagulation and plug formation? - Thrombocytes (Platelets)
• What is the normal resting arterial blood pressure of a healthy adult human? - 120/80 mmHg (Systolic/Diastolic)
• Which clinical instrument is used by medical practitioners to measure arterial blood pressure? - Sphygmomanometer
• Which blood vessels carry oxygenated blood under high pressure away from the heart? - Arteries
• Which exceptional artery carries deoxygenated blood from the right ventricle to the lungs? - Pulmonary Artery
• Which exceptional vein carries oxygenated blood from the lungs into the left atrium? - Pulmonary Vein
• What is the largest systemic artery in the human body originating from the left ventricle? - Aorta
• Which soluble plasma protein is converted by thrombin into insoluble fibrin strands during blood clotting? - Fibrinogen
• What natural anticoagulant polysaccharide produced by mast cells prevents intravascular clotting? - Heparin
• What X-linked genetic bleeding disorder impairs the body's ability to form blood clots? - Hemophilia
• What is the fluid portion of blood remaining after removing cellular elements called? - Plasma (approx. 55% of total blood)
• What is blood plasma called when fibrinogen and clotting factors have been removed? - Serum
• What microscopic air sacs in the human lungs serve as the primary site of gas exchange? - Alveoli
• What dome-shaped skeletal muscle contracts downward to drive pulmonary inspiration? - Diaphragm
• What double-layered serous membrane encloses and protects each lung? - Pleura
• What conjugated protein pigment containing four heme groups binds reversibly to oxygen in RBCs? - Hemoglobin
• How many oxygen molecules ($\text{O}_2$) can be bound and transported by a single hemoglobin molecule? - Four
• What toxic gas binds to hemoglobin with an affinity over 200 times higher than oxygen, causing asphyxiation? - Carbon Monoxide (CO)
• What stable bright cherry-red complex is formed when carbon monoxide binds to hemoglobin? - Carboxyhemoglobin
• In what chemical form is the majority (approx. 70%) of metabolic carbon dioxide transported in blood plasma? - Bicarbonate Ions ($\text{HCO}_3^-$)
• What RBC enzyme catalyzes the rapid conversion of dissolved $\text{CO}_2$ and water into carbonic acid? - Carbonic Anhydrase
• What initial anaerobic stage of cellular respiration splits glucose into two pyruvate molecules? - Glycolysis (EMP Pathway)
• Where inside the eukaryotic cell does glycolysis occur? - Cytoplasm (Cytosol)
• What is the net yield of ATP molecules produced per glucose molecule during glycolysis alone? - 2 ATP
• What aerobic cyclic metabolic pathway takes place inside the mitochondrial matrix to oxidize acetyl-CoA? - Krebs Cycle (Citric Acid Cycle)
• What biochemical pathway on the inner mitochondrial membrane generates the bulk of cellular ATP? - Electron Transport Chain (Oxidative Phosphorylation)
• What is the total theoretical net yield of ATP generated from the complete aerobic respiration of one glucose molecule? - 36 to 38 ATP
• What end product accumulates in human skeletal muscle fibers during strenuous anaerobic exercise, causing fatigue? - Lactic Acid
• What is the normal resting respiratory rate in a healthy adult human? - 12 to 16 Breaths per Minute
• What is the volume of air inspired or expired during a single normal relaxed breath called? - Tidal Volume (approx. 500 mL)
• Which region of the human brainstem houses the primary respiratory rhythm center? - Medulla Oblongata
• What cartilage flap covers the glottis during swallowing to prevent food from entering the trachea? - Epiglottis
• What is the common passage for both air and ingested food in the human throat called? - Pharynx
• What is the human cartilaginous voice box containing vocal cords called? - Larynx
• What is the normal resting heart rate of a healthy adult human? - 72 Beats per Minute

3. Human Organ Systems: Excretory, Nervous and Endocrine Systems

• What is the primary structural and functional microscopic filtration unit of the human kidney? - Nephron
• Approximately how many nephrons are contained within each healthy human kidney? - Approximately 1 Million
• What cup-shaped epithelial sac encloses the glomerular capillary network in a nephron? - Bowman’s Capsule
• What high-pressure capillary network inside Bowman's capsule carries out non-selective ultrafiltration? - Glomerulus
• In which organ of the human body is toxic ammonia converted into urea via the Ornithine Cycle? - Liver
• What nitrogenous waste product is the primary excretory solute in human urine? - Urea (Ureotelic)
• What yellowish breakdown pigment derived from hemoglobin gives human urine its color? - Urochrome
• What is the typical daily volume of urine excreted by a healthy adult human? - 1.0 to 1.5 Liters
• What hormone secreted by the posterior pituitary promotes water reabsorption in renal collecting ducts? - Antidiuretic Hormone (ADH / Vasopressin)
• A deficiency of ADH secretion causes which condition marked by excessive dilute urination? - Diabetes Insipidus
• What chemical compound comprises the majority of human kidney stones (renal calculi)? - Calcium Oxalate
• What medical procedure filters metabolic wastes and excess fluid from blood during acute renal failure? - Hemodialysis (Artificial Kidney)
• What muscular tubes propel urine from the renal pelvis into the urinary bladder via peristalsis? - Ureters
• What is the primary structural and functional excitable cell of the nervous system? - Neuron
• What insulating lipid sheath wraps around neuronal axons to speed up electrical nerve impulse conduction? - Myelin Sheath
• What are the microscopic gaps along a myelinated axon where action potentials regenerate called? - Nodes of Ranvier
• What microscopic junction separates two communicating neurons where neurotransmitters are released? - Synapse
• What common chemical neurotransmitter transmits impulses across neuromuscular junctions? - Acetylcholine
• What three protective connective tissue membranes enclose the human brain and spinal cord? - Meninges (Dura, Arachnoid, and Pia mater)
• What clear shock-absorbing fluid circulates through the subarachnoid space and brain ventricles? - Cerebrospinal Fluid (CSF)
• Which largest part of the human brain controls memory, voluntary motor movements, intelligence, and conscious thought? - Cerebrum (Cerebral Cortex)
• What thick band of nerve fibers connects and facilitates communication between the two cerebral hemispheres? - Corpus Callosum
• Which part of the hindbrain coordinates voluntary muscle movement, balance, and posture? - Cerebellum
• Which brainstem region controls autonomic vegetative reflexes such as heart rate, breathing, and swallowing? - Medulla Oblongata
• Which brain region acts as the central autonomic thermostat regulating body temperature, hunger, and thirst? - Hypothalamus
• What rapid, involuntary, unconscious motor response is mediated directly through the spinal cord? - Reflex Action
• Which small endocrine gland located in the sella turcica of the sphenoid bone is termed the 'Master Gland'? - Pituitary Gland (Hypophysis)
• Which hormone secreted by the anterior pituitary stimulates somatic growth and bone elongation? - Growth Hormone (Somatotropin)
• What endocrine disorder is caused by hypersecretion of growth hormone during childhood? - Gigantism
• What clinical condition results from hypersecretion of growth hormone in adulthood? - Acromegaly
• What condition is caused by hyposecretion of growth hormone during childhood? - Pituitary Dwarfism
• Which butterfly-shaped endocrine gland is located in the anterior neck overlying the trachea? - Thyroid Gland
• Which iodine-containing hormone secreted by the thyroid gland sets the basal metabolic rate (BMR)? - Thyroxine ($\text{T}_4$)
• What severe childhood condition of physical stunting and cognitive deficit is caused by congenital hypothyroidism? - Cretinism
• What adult hypothyroid condition is marked by lethargy, weight gain, and facial puffiness? - Myxedema
• What autoimmune hyperthyroid condition causes exophthalmos (protruding eyeballs) and weight loss? - Graves’ Disease
• Which hormone secreted by the parathyroid glands increases blood calcium levels by mobilizing calcium from bone? - Parathyroid Hormone (PTH / Parathormone)
• Which thyroid hormone opposes PTH by lowering blood calcium levels? - Calcitonin
• Which dual-function heterocrine gland contains the endocrine Islets of Langerhans? - Pancreas
• Which peptide hormone secreted by the Beta cells of the islets lowers blood glucose levels? - Insulin
• What metabolic disease is caused by an absolute deficiency or peripheral resistance to insulin? - Diabetes Mellitus
• Which hormone secreted by pancreatic Alpha cells stimulates hepatic glycogenolysis to raise blood glucose? - Glucagon
• Which paired endocrine glands sit like caps on the superior pole of each human kidney? - Adrenal Glands (Suprarenal Glands)
• Which hormone secreted by the adrenal medulla triggers the acute 'Fight or Flight' response? - Adrenaline (Epinephrine)
• Which mineralocorticoid steroid hormone produced by the adrenal cortex regulates sodium and potassium balance? - Aldosterone
• What primary glucocorticoid 'stress hormone' is synthesized by the adrenal cortex? - Cortisol
• Which hormone secreted by the pineal gland regulates circadian rhythms and sleep-wake cycles? - Melatonin
• Which primary androgenic steroid hormone is produced by the Leydig cells of the testes? - Testosterone
• Which steroid hormone produced by developing ovarian follicles regulates female secondary sexual characteristics? - Estrogen
• Which hormone produced by the corpus luteum maintains the endometrium during pregnancy? - Progesterone

4. Human Diseases, Immunity and Vaccines

• Which protozoan parasite causes malaria in humans? - Plasmodium (e.g., Plasmodium falciparum, P. vivax)
• Which mosquito vector transmits the human malaria parasite between hosts? - Infected Female Anopheles Mosquito
• Which protozoan disease transmitted by the sandfly vector causes visceral leishmaniasis? - Kala-Azar (Black Fever / Leishmania donovani)
• Which flagellated protozoan transmitted by the tsetse fly causes African Sleeping Sickness? - Trypanosoma brucei
• Which mosquito vector transmits the viral pathogens causing Dengue fever, Chikungunya, and Zika? - Female Aedes aegypti Mosquito
• Which mosquito vector transmits Wuchereria bancrofti, the causative worm of lymphatic Filariasis (Elephantiasis)? - Female Culex Mosquito
• Which acid-fast bacterium causes human Tuberculosis (TB)? - Mycobacterium tuberculosis
• What standardized live-attenuated childhood vaccine confers protection against Tuberculosis? - BCG Vaccine (Bacillus Calmette-Guérin)
• Which rod-shaped bacterium causes Typhoid (Enteric) fever? - Salmonella Typhi
• Which standard clinical serological test is used to confirm a diagnosis of Typhoid? - Widal Test
• Which comma-shaped bacterium causes acute watery diarrhea in Cholera? - Vibrio cholerae
• Which toxin-producing bacterium causes lockjaw and muscle spasms in Tetanus? - Clostridium tetani
• Which bacterium causes human Diphtheria, forming a pseudomembrane across the pharynx? - Corynebacterium diphtheriae
• What combination vaccine protects infants against Diphtheria, Pertussis (Whooping Cough), and Tetanus? - DPT Vaccine (Triple Antigen)
• Which fatal neurotropic virus transmitted via the saliva of rabid animals induces severe hydrophobia? - Rabies Virus (Rhabdovirus)
• Which single-stranded RNA retrovirus attacks $\text{CD4}^+$ T-helper cells, leading to AIDS? - Human Immunodeficiency Virus (HIV)
• What is the standard diagnostic screening enzyme assay used to detect antibodies against HIV? - ELISA (Enzyme-Linked Immunosorbent Assay)
• What confirmatory protein-banding test was traditionally used to validate positive HIV ELISA results? - Western Blot Test
• Which enterovirus infects spinal motor neurons, causing infantile paralysis? - Poliovirus
• Who developed the first inactivated injectable Polio vaccine (IPV) in 1952? - Jonas Salk
• Who developed the widely utilized live-attenuated Oral Polio Vaccine (OPV) in 1961? - Albert Sabin
• Which respiratory viral pathogen caused the worldwide COVID-19 pandemic? - SARS-CoV-2 (Coronavirus)
• Which infectious orthopoxvirus was declared eradicated worldwide in 1980 following universal vaccination? - Smallpox (Variola Virus)
• Who developed the first successful smallpox vaccine in 1796 using cowpox pustule material? - Edward Jenner
• Who established the Germ Theory of Disease, discovered rabies vaccination, and invented pasteurization? - Louis Pasteur
• Who discovered the first clinical antibiotic, Penicillin, derived from Penicillium notatum molds in 1928? - Alexander Fleming
• Who formulated the definitive Postulates of Disease Causation and identified the anthrax and TB bacilli? - Robert Koch
• What fungal infection commonly causes itchy circular skin lesions known as 'Ringworm'? - Tinea (Trichophyton / Microsporum fungi)
• Which fungal pathogen causes the foot infection clinically termed 'Athlete’s Foot'? - Trichophyton rubrum
• What type of immunity is acquired when the host's own immune system produces antibodies following exposure or vaccination? - Active Immunity
• What type of immunity is acquired by directly receiving preformed antibodies (e.g., maternal colostrum or anti-rabies serum)? - Passive Immunity
• What primary antibody isotype is concentrated in maternal colostrum, providing mucosal defense to newborns? - Immunoglobulin A (IgA)
• What is the only maternal immunoglobulin class that crosses the human placenta into fetal circulation? - Immunoglobulin G (IgG)
• Which immunoglobulin isotype mediates acute Type-I hypersensitivity and allergic anaphylactic responses? - Immunoglobulin E (IgE)
• What is an exaggerated immune hypersensitivity response to an otherwise harmless environmental antigen called? - Allergy
• What chemical released by mast cells and basophils triggers local vasodilation and itching during allergies? - Histamine
• What condition occurs when the immune system fails to recognize self-antigens and attacks host tissues? - Autoimmune Disease
• Name a classic autoimmune disease that destroys synovial joint linings. - Rheumatoid Arthritis
• What sexually transmitted bacterium causes Syphilis, presenting with a painless hard chancre? - Treponema pallidum
• What sexually transmitted bacterium causes Gonorrhea? - Neisseria gonorrhoeae
• What childhood viral infection presents with painful bilateral swelling of the parotid salivary glands? - Mumps (Paramyxovirus)
• What viral respiratory disease characterized by high fever and a maculopapular rash is prevented by the MMR vaccine? - Measles (Rubeola)
• What bacterial infection of the lungs causes alveolar consolidation with fluid and inflammatory exudate? - Pneumonia (Streptococcus pneumoniae)
• What genetic hemoglobinopathy caused by a single amino acid substitution causes RBCs to sickle under hypoxia? - Sickle Cell Anemia
• What inherited genetic blood disorder impairs alpha or beta globin chain synthesis, requiring lifelong transfusions? - Thalassemia
• What chromosomal trisomy-21 condition causes cognitive disability and distinctive epicanthic folds? - Down Syndrome
• What sex-linked genetic condition impairs the ability to distinguish between red and green spectral hues? - Color Blindness
• What vector-borne viral disease causing sudden hemorrhagic jaundice is transmitted by forest mosquitoes in the tropics? - Yellow Fever
• What medical preparations contain weakened, killed, or subunit pathogens administered to induce immunological memory? - Vaccines
• What phenomenon protects unimmunized individuals when a large percentage of a population is immune to a pathogen? - Herd Immunity

5. Plant Physiology, Botany and Cell Biology

• What is the biochemical process by which autotrophic green plants synthesize glucose using sunlight, $\text{CO}_2$, and $\text{H}_2\text{O}$? - Photosynthesis
• What green light-absorbing pigment is located inside the thylakoid membranes of chloroplasts? - Chlorophyll
• What central divalent metallic cation is chelated at the center of the chlorophyll porphyrin ring? - Magnesium ($\text{Mg}^{2+}$)
• During the light-dependent reactions of photosynthesis, molecular oxygen ($\text{O}_2$) is released from the photolysis of what molecule? - Water ($\text{H}_2\text{O}$)
• Where do the light-dependent reactions of photosynthesis take place within the chloroplast? - Thylakoid / Grana Membranes
• Where do the light-independent dark reactions (Calvin Cycle / $\text{C}_3$ Pathway) take place in a chloroplast? - Stroma
• What primary carboxylating enzyme catalyzes carbon dioxide fixation in the Calvin Cycle? - RuBisCO
• What microscopic pores on leaf surfaces facilitate photosynthetic gas exchange and transpiration? - Stomata
• What specialized paired epidermal cells regulate the turgor-driven opening and closing of a stoma? - Guard Cells
• Which complex vascular tissue conducts water and dissolved inorganic minerals upward from roots to leaves? - Xylem
• What physical cohesive and transpirational pulling mechanism drives the ascent of sap through xylem tracheary elements? - Transpiration Pull (Cohesion-Tension Theory)
• Which vascular tissue translocates photosynthesized sucrose bidirectionally from source to sink tissues? - Phloem
• What specialized living conducting cells in angiosperm phloem lack nuclei at maturity? - Sieve Tube Elements
• What nucleated parenchyma cells are closely connected to sieve tubes to maintain their metabolic functions? - Companion Cells
• What physiological process describes the evaporative loss of water vapor from the aerial surfaces of a plant? - Transpiration
• Which plant hormone promotes stem elongation, apical dominance, and phototropic bending toward light? - Auxin (Indole-3-Acetic Acid - IAA)
• Which plant hormone breaks seed dormancy, induces bolting in rosette plants, and stimulates alpha-amylase synthesis? - Gibberellin ($\text{GA}_3$)
• Which plant hormone stimulates active cell division, lateral shoot branching, and delays leaf senescence? - Cytokinin (e.g., Zeatin)
• Which gaseous phytohormone regulates natural fruit ripening and leaf abscission? - Ethylene
• Which plant stress hormone promotes stomatal closure during water deficit and maintains seed dormancy? - Abscisic Acid (ABA)
• What is the directional growth response of a plant shoot toward a unilateral light stimulus called? - Phototropism
• What is the directional growth response of plant roots downward toward Earth's gravitational center called? - Positive Geotropism / Gravitropism
• What is the rapid, non-directional seismonastic folding of Mimosa pudica ('Touch-Me-Not') leaflets upon touch called? - Thigmonasty
• What male reproductive organ of a flower consists of a supporting filament and a pollen-producing anther? - Stamen (Androecium)
• What female reproductive organ of a flower consists of a receptive stigma, style, and basal ovary? - Pistil / Carpel (Gynoecium)
• What botanical process transfers pollen grains from an anther onto the receptive stigma of a flower? - Pollination
• Following successful double fertilization in angiosperms, what structure does the fertilized ovule develop into? - Seed
• Following fertilization, what structure does the enlarged botanical ovary mature into? - Fruit
• What unique triploid ($3n$) nutritive tissue forms inside angiosperm seeds following double fertilization? - Endosperm
• Who first observed and coined the biological term 'Cell' in 1665 while examining cork slices under a microscope? - Robert Hooke
• Who first observed and described living, motile single-celled microorganisms (bacteria, protozoa, and sperm)? - Antonie van Leeuwenhoek
• Which two scientists formally formulated the classical Cell Theory in 1838–1839? - Matthias Schleiden and Theodor Schwann
• Who contributed the biological principle "Omnis cellula e cellula" (all living cells arise from pre-existing cells) in 1855? - Rudolf Virchow
• What rigid, protective outer structural layer made of cellulose microfibrils surrounds plant cells but is absent in animal cells? - Cell Wall
• What double-membraned organelle is designated as the 'Powerhouse of the Cell' for generating ATP? - Mitochondrion
• What are the inner folded convolutions of the inner mitochondrial membrane that house respiratory complexes called? - Cristae
• What high-energy ribonucleotide serves as the universal chemical energy currency of all living cells? - ATP (Adenosine Triphosphate)
• Which hydrolytic enzyme-filled acidic organelles are known as the 'Suicide Bags' of the cell? - Lysosomes
• Which non-membrane-bound cellular ribonucleoprotein complexes serve as the sites of protein synthesis? - Ribosomes
• Which membranous organelle studded with surface ribosomes processes and folds nascent polypeptide chains? - Rough Endoplasmic Reticulum (RER)
• Which organelle synthesizes lipids and phospholipids and detoxifies metabolic drugs and poisons? - Smooth Endoplasmic Reticulum (SER)
• Which stack of membrane-bound cisternae modifies, sorts, and packages proteins for transport? - Golgi Apparatus (Golgi Body)
• Which large, membrane-bound central organelle stores cell sap and maintains turgor pressure in mature plant cells? - Central Vacuole
• What selectively permeable single membrane encloses the central vacuole in plant cells? - Tonoplast
• Which organelle serves as the genetic control center of a eukaryotic cell, containing linear DNA chromosomes? - Nucleus
• What dense, non-membrane-bound subnuclear structure is the site of ribosomal RNA (rRNA) transcription and ribosome assembly? - Nucleolus
• What linear double-helical polymer carries hereditary genetic instructions in nearly all living cells? - DNA (Deoxyribonucleic Acid)
• Who discovered the molecular double-helix configuration of DNA in 1953 using X-ray diffraction data? - James Watson and Francis Crick
• Which nitrogenous purine base always pairs with Thymine in a double-stranded DNA molecule? - Adenine (A)
• Which nitrogenous base replaces Thymine in single-stranded RNA molecules? - Uracil (U)
• What type of cellular division results in two genetically identical diploid ($2n$) somatic daughter cells? - Mitosis