Download MTTC Biology (17) Test Exam and more Exams Technology in PDF only on Docsity!
Question 1. Which of the following best characterizes a scientific theory? A) An untested idea B) A well-substantiated explanation based on evidence C) A guess made by scientists D) A mathematical law Answer: B Explanation: A scientific theory is a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence and has stood up to repeated testing. Question 2. What is the primary purpose of a controlled experiment? A) To prove a hypothesis correct B) To isolate the effect of a single variable C) To eliminate all variables D) To observe natural phenomena without interference Answer: B Explanation: Controlled experiments manipulate one independent variable at a time, allowing researchers to determine its specific effect. Question 3. Which statement about scientific laws is TRUE? A) They explain why phenomena occur B) They describe patterns observed in nature C) They are unchangeable facts D) They predict future events with 100% certainty Answer: B Explanation: Scientific laws describe consistent patterns observed in nature, but do not explain the mechanisms behind them. Question 4. Which of the following exemplifies a hypothesis? A) Oxygen is necessary for combustion. B) Water boils at 100°C at sea level.
C) If plants are given fertilizer, then they will grow taller. D) The cell is the basic unit of life. Answer: C Explanation: A hypothesis is a testable prediction, often presented in an "If...then..." format. Question 5. What is the primary difference between a theory and a model in science? A) Theories are graphical, models are verbal B) Models are used to represent systems; theories explain phenomena C) Models are always physical objects D) Theories are not based on evidence Answer: B Explanation: Models are simplified representations of systems; theories are broad explanations based on evidence. Question 6. Which statistical method would be most appropriate to compare the means of two independent groups? A) Chi-square test B) t-test C) Regression analysis D) ANOVA Answer: B Explanation: A t-test is used to determine if there is a significant difference between the means of two independent groups. Question 7. What does "validity" refer to in a scientific investigation? A) The accuracy and appropriateness of the conclusions B) The consistency of measurements C) The ability to replicate results D) The number of trials performed Answer: A
C) A set of laws D) An unchanging protocol Answer: B Explanation: The scientific method is a flexible, iterative process used to investigate questions and test hypotheses. Question 12. What was the significance of Louis Pasteur’s experiments with swan-necked flasks? A) They supported spontaneous generation B) They disproved spontaneous generation C) They proved viruses cause disease D) They discovered DNA Answer: B Explanation: Pasteur's experiments demonstrated that microorganisms come from other microorganisms, not spontaneous generation. Question 13. Which concept states that the cell is the basic structural and functional unit of life? A) Germ theory B) Cell theory C) Endosymbiotic theory D) Theory of relativity Answer: B Explanation: Cell theory states that all living things are made of cells, the basic unit of life. Question 14. Which scientist is known for discovering the structure of DNA? A) Charles Darwin B) Rosalind Franklin C) Watson and Crick D) Robert Hooke Answer: C
Explanation: James Watson and Francis Crick are credited with the discovery of the double helix structure of DNA, using Franklin's data. Question 15. What is the role of peer review in scientific research? A) To increase funding for research B) To ensure the accuracy and quality of scientific publications C) To guarantee all research is correct D) To speed up publication Answer: B Explanation: Peer review helps maintain the integrity and quality of scientific literature. Question 16. Which of the following is an example of biology’s impact on technology? A) The invention of the steam engine B) The development of CRISPR gene editing C) The discovery of gravity D) The creation of the periodic table Answer: B Explanation: CRISPR gene editing is a biotechnology with significant biological foundation and impact. Question 17. What is the primary ethical concern with human gene editing technologies? A) The cost of equipment B) The potential for unintended consequences and misuse C) The speed of the process D) The need for batteries Answer: B Explanation: Ethical concerns include unintended genetic effects and misuse for non-therapeutic purposes. Question 18. Which of the following is NOT a responsibility of scientists in society?
Explanation: Proteins, specifically enzymes, catalyze biochemical reactions. Question 22. Which of the following best describes osmosis? A) Movement of solute from high to low concentration B) Movement of water from high to low solute concentration C) Movement of water across a semipermeable membrane from low to high solute concentration D) Active transport of ions Answer: C Explanation: Osmosis is the passive movement of water across a membrane toward higher solute concentration. Question 23. Which property of water enables it to dissolve many substances? A) Low density B) Nonpolarity C) Polarity D) High melting point Answer: C Explanation: Water's polarity allows it to be an excellent solvent for ionic and polar substances. Question 24. Which statement about prokaryotic and eukaryotic cells is true? A) Only prokaryotic cells have a nucleus B) Only eukaryotic cells have membrane-bound organelles C) Both have mitochondria D) Only prokaryotes have DNA Answer: B Explanation: Eukaryotic cells have membrane-bound organelles; prokaryotes do not. Question 25. The main structural component of plant cell walls is: A) Starch
B) Cellulose C) Glycogen D) Chitin Answer: B Explanation: Cellulose is a carbohydrate polymer that forms the structural framework of plant cell walls. Question 26. What is the function of ribosomes in cells? A) DNA replication B) Protein synthesis C) ATP production D) Lipid storage Answer: B Explanation: Ribosomes synthesize proteins by translating mRNA. Question 27. The process by which green plants convert light energy into chemical energy is called: A) Cellular respiration B) Photosynthesis C) Fermentation D) Glycolysis Answer: B Explanation: Photosynthesis uses light energy to produce glucose from CO₂ and water. Question 28. Which of the following organelles is responsible for modifying, sorting, and packaging proteins? A) Nucleus B) Mitochondrion C) Golgi apparatus D) Lysosome Answer: C
B) Crossing over C) Cytokinesis D) Binary fission Answer: B Explanation: Crossing over exchanges genetic material between homologous chromosomes, increasing variation. Question 33. What is the function of the chloroplast? A) Cellular respiration B) Protein synthesis C) Photosynthesis D) DNA replication Answer: C Explanation: Chloroplasts capture light energy to perform photosynthesis in plant cells. Question 34. Which molecule is the universal energy currency of the cell? A) DNA B) Glucose C) ATP D) NADPH Answer: C Explanation: ATP (adenosine triphosphate) stores and transfers energy for cellular processes. Question 35. The semi-permeable nature of the cell membrane is primarily due to: A) Cellulose fibers B) Phospholipid bilayer C) Protein channels only D) DNA content Answer: B
Explanation: The phospholipid bilayer forms a selectively permeable barrier for the cell. Question 36. Which process describes the uptake of large molecules into a cell by engulfing them in a vesicle? A) Diffusion B) Osmosis C) Endocytosis D) Exocytosis Answer: C Explanation: Endocytosis involves the engulfment of extracellular material into the cell. Question 37. Which of the following best describes facilitated diffusion? A) Movement of molecules through protein channels without energy input B) Active movement of molecules requiring ATP C) Bulk transport of fluids D) Movement of water across a membrane Answer: A Explanation: Facilitated diffusion allows molecules to cross membranes via protein channels, without energy. Question 38. Which phase of mitosis involves the alignment of chromosomes at the cell's equator? A) Prophase B) Metaphase C) Anaphase D) Telophase Answer: B Explanation: During metaphase, chromosomes align at the metaphase plate (equator). Question 39. Which of the following is NOT a function of the smooth endoplasmic reticulum?
D) Transport of molecules Answer: B Explanation: Proteins perform many roles, but energy storage is primarily a function of carbohydrates and lipids. Question 43. In which phase of the cell cycle does DNA replication occur? A) G1 phase B) S phase C) G2 phase D) M phase Answer: B Explanation: DNA replication takes place during the synthesis (S) phase of interphase. Question 44. Which scientist is known for discovering the laws of inheritance using pea plants? A) Charles Darwin B) Louis Pasteur C) Gregor Mendel D) Barbara McClintock Answer: C Explanation: Gregor Mendel established the fundamental laws of inheritance through experiments with pea plants. Question 45. What is the role of tRNA during translation? A) Carrying amino acids to the ribosome B) Transcribing DNA into RNA C) Synthesizing ATP D) Replicating DNA Answer: A Explanation: tRNA brings specific amino acids to the ribosome during protein synthesis.
Question 46. Which of the following is an example of non-nuclear inheritance? A) Mitochondrial DNA inheritance B) Inheritance of the Y chromosome C) Chromosomal crossover D) Mutations in nuclear DNA Answer: A Explanation: Mitochondrial DNA is inherited maternally and is located outside the nucleus. Question 47. Which process directly results in two genetically identical daughter cells? A) Meiosis B) Binary fission C) Mitosis D) Fertilization Answer: C Explanation: Mitosis produces two identical daughter cells. Question 48. Which term describes a change in the DNA sequence? A) Translation B) Mutation C) Transcription D) Replication Answer: B Explanation: A mutation is any alteration in the DNA sequence. Question 49. What is the purpose of gel electrophoresis in molecular biology? A) Replicating DNA B) Separating DNA fragments by size C) Editing genes
Question 53. Which mechanism introduces new alleles into a population? A) Genetic drift B) Mutation C) Natural selection D) Non-random mating Answer: B Explanation: Mutation is the original source of new alleles in a gene pool. Question 54. Gene flow involves: A) Movement of genes between different populations B) Random loss of alleles C) Cloning of genes D) Transcription of genes Answer: A Explanation: Gene flow is the exchange of genes between populations, increasing genetic diversity. Question 55. Which process occurs during the light-dependent reactions of photosynthesis? A) Glucose is synthesized B) Water is split, releasing oxygen C) Carbon dioxide is fixed D) ATP is used to build sugars Answer: B Explanation: Light-dependent reactions split water to release oxygen, producing ATP and NADPH. Question 56. The Calvin cycle occurs in the: A) Cytoplasm B) Mitochondria C) Thylakoid membrane D) Stroma of chloroplasts
Answer: D Explanation: The Calvin cycle (light-independent reactions) occurs in the stroma of chloroplasts. Question 57. Which of the following is an example of artificial selection? A) Peppered moth color change B) Breeding dogs for specific traits C) Antibiotic resistance D) Industrial melanism Answer: B Explanation: Artificial selection is the intentional breeding for desired traits by humans. Question 58. Which evidence supports the endosymbiotic theory? A) Mitochondria have their own DNA B) Chloroplasts are found only in animals C) Prokaryotes have nuclei D) Eukaryotic cells lack organelles Answer: A Explanation: The presence of DNA, ribosomes, and double membranes in mitochondria and chloroplasts supports endosymbiosis. Question 59. What is the main function of the lysosome? A) Protein synthesis B) Cellular digestion and waste removal C) Lipid storage D) Energy production Answer: B Explanation: Lysosomes contain digestive enzymes that break down waste and cellular debris. Question 60. Which of the following best describes coevolution?
Answer: B Explanation: Louis Pasteur's experiments disproved spontaneous generation. Question 64. In DNA replication, which enzyme adds complementary nucleotides to the growing strand? A) DNA ligase B) DNA helicase C) DNA polymerase D) RNA polymerase Answer: C Explanation: DNA polymerase synthesizes the new DNA strand by adding complementary nucleotides. Question 65. Which of the following structures is found only in prokaryotic cells? A) Nucleus B) Mitochondria C) Nucleoid D) Endoplasmic reticulum Answer: C Explanation: Prokaryotes have a nucleoid region instead of a membrane-bound nucleus. Question 66. Which level of protein structure is determined by the sequence of amino acids? A) Primary B) Secondary C) Tertiary D) Quaternary Answer: A Explanation: The primary structure is the unique sequence of amino acids in a protein. Question 67. What is the main function of NADPH in photosynthesis? A) Absorb light
B) Store energy as glucose C) Provide electrons for the Calvin cycle D) Generate ATP Answer: C Explanation: NADPH delivers electrons and hydrogen to drive sugar synthesis in the Calvin cycle. Question 68. Which process uses mRNA as a template to assemble amino acids into a polypeptide? A) Replication B) Transcription C) Translation D) Mutation Answer: C Explanation: Translation uses mRNA to direct protein synthesis at the ribosome. Question 69. What is the significance of the fossil record to evolutionary biology? A) It shows all species alive today B) It provides evidence of changes in life forms over time C) It proves all life originated at the same time D) It only contains extinct species Answer: B Explanation: The fossil record demonstrates historical changes and transitional forms of life. Question 70. Which of the following is an ethical issue related to cloning technology? A) Increased crop yields B) Loss of genetic diversity C) Improved disease diagnosis D) Increased soil fertility Answer: B Explanation: Cloning can reduce genetic diversity, raising ethical and ecological concerns.
