BIO 202 Exam 1 - Practice Questions & Answers - PDF

Sure! Here’s an expanded set of questions with answers to help you prepare for your BIO 202 Exam 1. BIO 202 Exam 1 - Practice Questions & Answers Chapter 2: Atoms & Molecules ​ 1.​ What are the three subatomic particles and their charges? ​ ​ Protons (+) ​ ​ Neutrons...

Sure! Here’s an expanded set of questions with answers to help you prepare for your BIO 202 Exam 1. BIO 202 Exam 1 - Practice Questions & Answers Chapter 2: Atoms & Molecules ​ 1.​ What are the three subatomic particles and their charges? ​ ​ Protons (+) ​ ​ Neutrons (0) ​ ​ Electrons (-) ​ 2.​ What is the difference between atomic number and mass number? ​ ​ Atomic number = Number of protons. ​ ​ Mass number = Sum of protons + neutrons. ​ 3.​ What makes isotopes different from each other? ​ ​ Same number of protons but different numbers of neutrons. ​ 4.​ What is radioactive decay? How is it used in biology? ​ ​ Unstable isotopes release radiation over time. ​ ​ Used in carbon dating, cancer treatment, and medical imaging. ​ 5.​ Compare covalent, ionic, and hydrogen bonds. ​ ​ Covalent: Atoms share electrons (strongest bond). ​ ​ Ionic: Transfer of electrons creates charged ions (Na⁺, Cl⁻). ​ ​ Hydrogen: Weak attraction between partial charges (e.g., H₂O molecules). ​ 6.​ What is electronegativity? How does it affect bonding? ​ ​ Electronegativity is an atom’s ability to attract electrons. ​ ​ High electronegativity (O, N) leads to polar bonds. Chapter 3: Water & Life ​ 7.​ Why does ice float on water? ​ ​ Ice is less dense than liquid water because hydrogen bonds push molecules apart in solid form. ​ 8.​ How does water’s high specific heat benefit life? ​ ​ Water absorbs & retains heat, helping maintain stable temperatures in organisms & environments. ​ 9.​ What is the difference between acids and bases? ​ ​ Acids: Increase H⁺ concentration (pH < 7). ​ ​ Bases: Increase OH⁻ concentration (pH > 7). ​ 10.​ What is a buffer? Why is it important? ​ ​ A buffer minimizes pH changes by absorbing or releasing H⁺. ​ ​ Example: Bicarbonate system in blood maintains pH ~7.4. Chapter 4: Carbon & Molecular Diversity ​ 11.​ Why is carbon so important in biological molecules? ​ ​ Carbon forms four covalent bonds, allowing for diverse organic molecules. ​ 12.​ What are the four ways carbon skeletons can vary? ​ ​ Length, branching, double bonds, rings. ​ 13.​ Match the functional group to its property: ​ ​ Hydroxyl (-OH) → Polar, found in alcohols. ​ ​ Carboxyl (-COOH) → Acidic, found in amino acids. ​ ​ Amino (-NH₂) → Basic, found in proteins. ​ ​ Phosphate (-PO₄) → Energy storage (ATP). Chapter 5: Macromolecules Carbohydrates ​ 14.​ What is the main function of carbohydrates? ​ ​ Energy storage (starch, glycogen) and structural support (cellulose, chitin). ​ 15.​ Why can humans digest starch but not cellulose? ​ ​ Humans have enzymes to break down starch, but lack enzymes to digest cellulose. Lipids ​ 16.​ What are the three main types of lipids? ​ ​ Fats, phospholipids, steroids. ​ 17.​ Why are phospholipids important? ​ ​ They form cell membranes (hydrophilic heads, hydrophobic tails). Proteins ​ 18.​ What determines a protein’s function? ​ ​ Its 3D shape (folding), which is determined by amino acid sequence. ​ 19.​ What happens if a protein is denatured? ​ ​ It loses its shape & function (caused by heat, pH changes). Nucleic Acids ​ 20.​ What are the three components of a nucleotide? ​ ​ Phosphate group, sugar, nitrogenous base. ​ 21.​ Compare DNA & RNA. ​ ​ DNA: Double-stranded, thymine (T), deoxyribose sugar. ​ ​ RNA: Single-stranded, uracil (U), ribose sugar. Chapter 6: Cell Structure & Function ​ 22.​ What are three key differences between prokaryotic and eukaryotic cells? ​ ​ Prokaryotic: No nucleus, circular DNA, small. ​ ​ Eukaryotic: Has nucleus, linear DNA, larger. ​ 23.​ Which organelle is the powerhouse of the cell? ​ ​ Mitochondria (produces ATP). ​ 24.​ Which organelles are found only in plant cells? ​ ​ Chloroplasts, central vacuole, cell wall. ​ 25.​ Match the organelle to its function: ​ ​ Nucleus → Stores DNA. ​ ​ Ribosomes → Protein synthesis. ​ ​ Golgi Apparatus → Modifies & ships proteins. ​ ​ Lysosomes → Digests enzymes waste. ​ ​ Mitochondria → Energy production. ​ ​ Chloroplasts → Photosynthesis. ​ 26.​ What is the endosymbiotic theory? You’re absolutely right! Here’s an expanded section covering chloroplasts, vacuoles, and the endoplasmic reticulum (smooth & rough ER), along with questions and answers for these topics. Cell Organelles & Their Functions Chloroplasts (Plant Cells Only) ​ ​ Function: Site of photosynthesis—converts light energy into chemical energy (glucose). ​ ​ Structure: ​ ​ Double membrane (like mitochondria). ​ ​ Thylakoids: Flattened sacs where light-dependent reactions occur. ​ ​ Grana: Stacks of thylakoids. ​ ​ Stroma: Fluid surrounding the thylakoids; where the Calvin cycle occurs. ​ ​ Found in: Plants & algae only (not in animal cells). ​ ​ Contain their own DNA & ribosomes (supports endosymbiotic theory). Vacuoles (Types & Functions) ​ ​ Vacuoles are membrane-bound sacs that store substances and help maintain cell structure. Type of Vacuole Found In Function Central Vacuole Plant cells Stores water, ions, nutrients; provides turgor pressure for structure. Food Vacuole Protists & some animals Formed by phagocytosis; stores engulfed food for digestion. Contractile Vacuole Freshwater protists (e.g., Pumps out excess water to Paramecium) prevent bursting (osmoregulation). Component,Function Nuclear Membrane,- Surrounds the nucleus and controls what enters and exits. Nuclear Pores,- Small holes in the membrane that allow things like RNA to pass through. Chromatin,- DNA and proteins that carry genetic information. Nucleolus,- Makes ribosomes, which help with protein production. Nucleoplasm,- The jelly-like substance inside the nucleus where everything floats. Nuclear envelope- is a double-layered membrane around the nucleus. ​ ​ It protects the DNA inside the nucleus. ​ ​ It has pores that control what can enter or leave the nucleus, like RNA and proteins. Think of it as a protective shield with gates that let certain things in and out. Endoplasmic Reticulum (ER) The ER is a network of membranes connected to the nuclear envelope. Rough ER (RER) ​ ​ Studded with ribosomes → Makes proteins that will be: ​ ​ Secreted from the cell (e.g., insulin). ​ ​ Incorporated into membranes. ​ ​ Sent to lysosomes. ​ ​ Modifies & folds proteins before sending them to the Golgi apparatus. Smooth ER (SER) ​ ​ Lacks ribosomes → Does not make proteins. ​ ​ Functions: ​ ​ Lipid & steroid synthesis (e.g., phospholipids for membranes). ​ ​ Detoxifies drugs & toxins (abundant in liver cells). ​ ​ Stores calcium ions (important in muscle contraction). Practice Questions & Answers Chloroplasts ​ 1.​ What is the main function of chloroplasts? ​ ​ To perform photosynthesis, converting light energy into glucose. ​ 2.​ What are the three main structures inside chloroplasts? ​ ​ Thylakoids (light reactions), grana (stacks of thylakoids), stroma (fluid for Calvin cycle). ​ 3.​ What is the evidence that chloroplasts originated from bacteria? ​ ​ Own DNA & ribosomes, double membrane, divide like bacteria (supports endosymbiotic theory). Vacuoles ​ 4.​ What is the function of the central vacuole in plant cells? ​ ​ Stores water, nutrients, and waste; provides turgor pressure for support. ​ 5.​ Which type of vacuole is responsible for expelling excess water in freshwater protists? ​ ​ Contractile vacuole (found in protists like Paramecium). ​ 6.​ How do food vacuoles form? ​ ​ By phagocytosis, when a cell engulfs food particles. Endoplasmic Reticulum (ER) ​ 7.​ What is the main structural difference between smooth and rough ER? ​ ​ Rough ER has ribosomes attached; Smooth ER does not. ​ 8.​ What type of molecules are synthesized in the smooth ER? ​ ​ Lipids, steroids, and phospholipids. ​ 9.​ Which type of ER detoxifies drugs and poisons? ​ ​ Smooth ER (abundant in liver cells). ​ 10.​ What happens to proteins made in the rough ER? ​ ​ They are folded, modified, and sent to the Golgi apparatus for processing. Component,Function Microfilaments,- Cell movement and shape changes (e.g., muscle contraction, cell crawling) ,- Cytokinesis (cell division) Intermediate Filaments,- Provide mechanical strength to resist stress and maintain cell structure ,- Structural support for the nucleus and other organelles Microtubules,- Maintain cell shape and rigidity ,- Aid in cell division (mitosis) ,- Serve as tracks for intracellular transport (e.g., vesicles, organelles) Cilia,- Move fluids or particles along the surface of the cell or tissue (e.g., in the respiratory tract),- Short and numerous (like tiny hairs) ,- Help with cell movement in some organisms (e.g., single-celled organisms),- Beat in coordinated waves Flagella,- Propel cells through liquid environments (e.g., sperm cells, some bacteria),- Long and usually few in number (typically 1 or 2) ,- Enable cell movement through a whip-like motion,- Move in a more undulating or “wave-like” motion ECM: consists of glycotproteins + other carbs secreted by cells (collagen, fibronectin, varies) Cell junctions - Plasmodesmata in plant cells: many plant cells are perforated w/ plasmodesmata – channels that connect cells - Plasma membrane line plasmodesmata – continuous - Cells share same internal chem env – unifies plant into one living continuum → helps transport water and small solutes t/o - In animal cells: tight junctions, desmosomes, gap junctions - Tight junctions: proteins bind the plasma membranes of 2 cells very tightly; prevents leakage - Gap junctions: channels from one cell to another ; lined with proteins; allows for communication b/w cells + movement of stuff - Desmosomes: fasten cells together into strong sheets Glycoproteins,Proteins with sugar molecules attached.,- Help with cell recognition and communication. ,,- Important in immune responses and cell signaling. Glycolipids,Lipids (fats) with sugar molecules attached.,- Found in cell membranes, help with cell recognition. ,,- Help cells interact with each other and protect the cell. Peroxisomes-,Small organelles filled with enzymes.,- Break down fatty acids and detoxify harmful substances (e.g., hydrogen peroxide). Extracellular Matrix (ECM),-The network of proteins and molecules outside the cell.,- Provides structural support to tissues. Intracellular Matrix,-The network inside the cell that supports organelles and other structures (often part of the cytoskeleton).,- Helps maintain cell shape and supports organelles. Motor Proteins,-Proteins like kinesin, dynein, and myosin that help cells move or move things inside cells.,- Involved in cell movement (e.g., muscle contraction) and transport of materials within cells.  Kinesis Microtubules + (Away from nucleus) Intracellular transport, mitosis Dyneis Microtubules - (Toward nucleus) Intracellular transport, cilia/flagella movement Myosis Actin filaments + (Mostly) Muscle contraction, vesicle transport Chapter 6: Microscopy & Cell Study Techniques Microscopy Basics ​ 27.​ What are the three main parameters of microscopy? ​ ​ Magnification: How much larger an object appears. ​ ​ Resolution: The clarity of an image; ability to distinguish two close objects. ​ ​ Contrast: The difference in brightness between parts of a sample. ​ 28.​ What are the two main types of microscopes? ​ ​ Light Microscope (LM): Uses visible light to view specimens. ​ ​ Electron Microscope (EM): Uses electron beams for much higher resolution. Light Microscopy (LM) ​ 29.​ What is the maximum magnification of a light microscope? ​ ​ About 1000x. ​ 30.​ What is the resolution limit of a light microscope? ​ ​ About 200 nm (0.2 µm). ​ 31.​ What are two common types of light microscopy? ​ ​ Brightfield Microscopy: Light passes directly through the specimen. ​ ​ Fluorescence Microscopy: Uses fluorescent dyes to highlight structures. Electron Microscopy (EM) ​ 32.​ How does an electron microscope differ from a light microscope? ​ ​ Uses electron beams instead of light, allowing much higher resolution. ​ 33.​ What is the resolution of an electron microscope? ​ ​ ~2 nm (100 times better than light microscopes). ​ 34.​ What are the two types of electron microscopes? ​ ​ Scanning Electron Microscope (SEM): ​ ​ Produces 3D images by scanning a specimen’s surface. ​ ​ Transmission Electron Microscope (TEM): ​ ​ Used to study internal structures by passing electrons through thin slices of cells. Specialized Microscopy Techniques ​ 35.​ What is confocal microscopy, and how does it improve resolution? ​ ​ Uses a laser beam to scan the sample, reducing out-of-focus light for clearer images. ​ 36.​ What is cryo-electron microscopy (Cryo-EM)? ​ ​ Samples are frozen at extremely low temperatures to preserve structures without fixatives. ​ 37.​ What is super-resolution microscopy? ​ ​ Uses computational techniques to exceed the resolution limit of traditional light microscopes. Cell Fractionation & Studying Organelles ​ 38.​ What is cell fractionation? ​ ​ A technique that breaks open cells and separates organelles based on size/density using centrifugation. ​ 39.​ Why is cell fractionation useful? ​ ​ Allows scientists to study organelles in isolation to understand their function. ​ 40.​ What tool is used for cell fractionation? ​ ​ Ultracentrifuge (spins samples at high speeds to separate cell components).