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Question 1. Which of the following is a key characteristic of scientific knowledge? A) It is based solely on intuition B) It is testable and falsifiable C) It is unchanged by new evidence D) It relies on authority alone Answer: B Explanation: Scientific knowledge must be testable and falsifiable, meaning claims can be examined and disproved if evidence contradicts them. Question 2. What distinguishes a scientific theory from a hypothesis? A) Theories are untestable B) Hypotheses are proven facts C) Theories have broad explanatory power and are supported by evidence D) Hypotheses are laws Answer: C Explanation: Theories are well-supported, comprehensive explanations; hypotheses are testable statements. Question 3. Who is credited with establishing the cell theory? A) Charles Darwin B) Gregor Mendel C) Matthias Schleiden and Theodor Schwann D) Louis Pasteur Answer: C Explanation: Schleiden and Schwann formulated the cell theory, stating that all living things are composed of cells. Question 4. Which of the following best describes the relationship between science, technology, and society? A) Science is unaffected by society
B) Technology is unrelated to science C) Science and technology influence and are influenced by societal needs and values D) Society always opposes technological advancements Answer: C Explanation: Science and technology both shape and are shaped by societal factors, including ethics and needs. Question 5. Which step comes first in the scientific method? A) Forming a hypothesis B) Analyzing data C) Making an observation D) Drawing conclusions Answer: C Explanation: Scientific inquiry typically begins with observations. Question 6. What is an independent variable in an experiment? A) The result measured B) The variable being changed or manipulated C) The variable held constant D) The variable that cannot be measured Answer: B Explanation: The independent variable is the one the experimenter changes to test its effect. Question 7. Why is a control group important in experimental design? A) It introduces bias B) It allows comparison to determine if the independent variable has an effect C) It increases error D) It is not necessary Answer: B
C) The hypothesis is false D) The experiment should be repeated Answer: B Explanation: Statistical significance suggests the result is likely real, not due to random variation. Question 12. Which SI unit is used to measure mass? A) Meter B) Second C) Kilogram D) Liter Answer: C Explanation: The kilogram is the SI unit for mass. Question 13. Which macromolecule is the primary source of energy for cellular processes? A) Nucleic acid B) Lipid C) Carbohydrate D) Protein Answer: C Explanation: Carbohydrates provide quick energy for cells. Question 14. What property of water allows it to be an excellent solvent? A) Nonpolarity B) High density C) Polarity D) Inertness Answer: C Explanation: Water’s polarity allows it to dissolve many substances.
Question 15. Which type of bond holds together the two strands of a DNA molecule? A) Ionic bonds B) Hydrogen bonds C) Covalent bonds D) Metallic bonds Answer: B Explanation: Hydrogen bonds connect nitrogenous bases between DNA strands. Question 16. Enzymes function as: A) Energy sources B) Structural components C) Biological catalysts D) Genetic material Answer: C Explanation: Enzymes speed up chemical reactions in living organisms. Question 17. Which factor does NOT affect enzyme activity? A) Temperature B) pH C) Substrate concentration D) Sound waves Answer: D Explanation: Sound waves do not influence enzyme activity. Question 18. Which organelle is responsible for energy production in animal cells? A) Nucleus B) Ribosome C) Mitochondrion D) Lysosome
B) ATP
C) DNA
D) NADH
Answer: B Explanation: ATP stores and provides energy for cellular activities. Question 23. What is the first stage of cellular respiration? A) Electron transport chain B) Krebs cycle C) Glycolysis D) Fermentation Answer: C Explanation: Glycolysis is the initial step, breaking down glucose. Question 24. Where does the Krebs cycle occur in eukaryotic cells? A) Nucleus B) Cytoplasm C) Mitochondrial matrix D) Chloroplast Answer: C Explanation: The Krebs cycle occurs in the mitochondrial matrix. Question 25. What is the main product of the light-dependent reactions of photosynthesis? A) Glucose B) ATP and NADPH C) Pyruvate D) Oxygen gas only Answer: B Explanation: ATP and NADPH are produced and used in the Calvin cycle.
Question 26. Which of the following correctly compares aerobic and anaerobic respiration? A) Both use oxygen B) Aerobic produces more ATP than anaerobic C) Anaerobic occurs only in plants D) Aerobic is less efficient Answer: B Explanation: Aerobic respiration yields more ATP than anaerobic. Question 27. What is the structure that contains genetic material in eukaryotic cells? A) Mitochondrion B) Nucleolus C) Nucleus D) Ribosome Answer: C Explanation: The nucleus houses DNA in eukaryotic cells. Question 28. During which phase do chromosomes align in the middle of the cell during mitosis? A) Prophase B) Metaphase C) Anaphase D) Telophase Answer: B Explanation: Chromosomes line up at the metaphase plate. Question 29. What is the main purpose of meiosis? A) Growth B) Repair C) Gamete production
A) Ligase B) Helicase C) RNA polymerase D) Endonuclease Answer: B Explanation: Helicase separates DNA strands for replication. Question 34. Which molecule carries amino acids to the ribosome during translation? A) mRNA B) tRNA C) rRNA D) DNA Answer: B Explanation: tRNA brings amino acids to the ribosome. Question 35. What is a codon? A) A segment of DNA that codes for a protein B) Three consecutive nucleotides on mRNA C) An enzyme D) A type of mutation Answer: B Explanation: A codon is a triplet on mRNA specifying an amino acid. Question 36. What regulates gene expression in prokaryotes? A) Operons B) Introns C) Nucleosomes D) Enhancers only Answer: A
Explanation: Operons allow prokaryotes to regulate gene transcription. Question 37. Which type of mutation involves a change in a single nucleotide? A) Chromosomal deletion B) Point mutation C) Duplication D) Inversion Answer: B Explanation: Point mutations affect one nucleotide base. Question 38. Mendel’s law of segregation states: A) Genes are always inherited together B) Each parent passes one allele for each trait to offspring C) Offspring inherit all alleles from one parent D) Genes are blended Answer: B Explanation: Each gamete receives only one allele for each gene. Question 39. What is the expected genotypic ratio in a monohybrid cross of two heterozygotes? A) 1:2: B) 3: C) 1: D) 9:3:3: Answer: A Explanation: The genotypic ratio for Aa x Aa is 1 AA : 2 Aa : 1 aa. Question 40. Which inheritance pattern is illustrated when both alleles are fully expressed in the phenotype? A) Incomplete dominance
Question 44. Which of the following is an ethical concern in genetic engineering? A) Increased crop yield B) Environmental impacts and gene transfer to non-target species C) Faster DNA replication D) Use of restriction enzymes Answer: B Explanation: Gene transfer to non-target organisms can have unforeseen consequences. Question 45. What is the main mechanism driving evolution? A) Intelligence B) Natural selection C) Random chance only D) Willpower Answer: B Explanation: Natural selection favors traits that improve survival and reproduction. Question 46. What is genetic drift? A) Movement of individuals between populations B) Random changes in allele frequencies C) Directed selection D) Non-random mating Answer: B Explanation: Genetic drift refers to random fluctuations in allele frequencies. Question 47. Which population is in Hardy-Weinberg equilibrium? A) Population with mutation, migration, and selection B) Population with random mating and no evolution C) Population with non-random mating
D) Population with high mutation rate Answer: B Explanation: Hardy-Weinberg equilibrium requires no evolutionary forces and random mating. Question 48. Which process often leads to the formation of new species? A) Mutation B) Mitosis C) Speciation D) Transcription Answer: C Explanation: Speciation is the process by which new species arise. Question 49. Which structure is an example of a homologous structure? A) Bird wing and butterfly wing B) Whale flipper and human arm C) Insect leg and plant stem D) Fish scale and reptile scale Answer: B Explanation: Homologous structures arise from common ancestry. Question 50. What do phylogenetic trees depict? A) Amount of DNA in a species B) Evolutionary relationships among organisms C) Age of fossils D) Biome types Answer: B Explanation: Phylogenetic trees illustrate how species are related through evolution. Question 51. Which pattern of evolution occurs when two unrelated species develop similar traits?
Explanation: Bacteria have peptidoglycan in their cell walls. Question 55. Which kingdom contains multicellular, photosynthetic eukaryotes? A) Fungi B) Animalia C) Plantae D) Protista Answer: C Explanation: Plantae includes multicellular plants. Question 56. Which structure is common to all viruses? A) Cell wall B) Nucleus C) Protein coat (capsid) D) Ribosome Answer: C Explanation: All viruses have a capsid; they lack cellular structure. Question 57. What is the ecological role of decomposers like fungi? A) Primary production B) Breaking down dead organic matter C) Photosynthesis D) Predation Answer: B Explanation: Decomposers recycle nutrients by decomposing dead matter. Question 58. Which plant group includes flowering plants? A) Gymnosperms B) Bryophytes
C) Angiosperms D) Ferns Answer: C Explanation: Angiosperms are flowering plants. Question 59. Which animal phylum includes insects, spiders, and crustaceans? A) Mollusca B) Arthropoda C) Annelida D) Chordata Answer: B Explanation: Arthropoda includes joint-legged invertebrates. Question 60. What is the main function of plant roots? A) Photosynthesis B) Absorption of water and minerals C) Reproduction D) Pollination Answer: B Explanation: Roots anchor plants and absorb water/nutrients. Question 61. Which plant tissue transports water from roots to leaves? A) Phloem B) Xylem C) Cortex D) Epidermis Answer: B Explanation: Xylem carries water upward in plants.
Answer: B Explanation: The integumentary system (skin) protects and regulates temperature. Question 66. Which bone type is responsible for blood cell formation? A) Flat bones B) Irregular bones C) Long bones (marrow) D) Short bones Answer: C Explanation: Long bones contain marrow that forms blood cells. Question 67. Which muscle type is under voluntary control? A) Cardiac B) Smooth C) Skeletal D) All of the above Answer: C Explanation: Skeletal muscle is voluntary; cardiac and smooth are involuntary. Question 68. What is the functional unit of the nervous system? A) Neuron B) Glial cell C) Muscle fiber D) Hormone Answer: A Explanation: Neurons transmit nerve impulses. Question 69. Which gland produces insulin? A) Thyroid
B) Adrenal C) Pituitary D) Pancreas Answer: D Explanation: The pancreas releases insulin to regulate blood sugar. Question 70. Which chamber of the human heart pumps blood to the lungs? A) Left ventricle B) Right ventricle C) Left atrium D) Right atrium Answer: B Explanation: The right ventricle sends blood to the lungs. Question 71. Where does gas exchange occur in the lungs? A) Bronchi B) Alveoli C) Trachea D) Diaphragm Answer: B Explanation: Alveoli are tiny sacs where oxygen and CO₂ are exchanged. Question 72. Which enzyme begins the digestion of starch in the mouth? A) Pepsin B) Amylase C) Lipase D) Lactase Answer: B Explanation: Salivary amylase breaks down starches.
