Bio Quiz #3 Notes PDF

Quiz #2 Organelles Organelle Function Cell Membrane ➔ Holds contents of the cell together ➔ Controls what enters/exits the cell ➔ Phospholipid bilayer (made of fats, proteins and...

Quiz #2 Organelles Organelle Function Cell Membrane ➔ Holds contents of the cell together ➔ Controls what enters/exits the cell ➔ Phospholipid bilayer (made of fats, proteins and carbohydrates) Cell Wall ➔ Supports structure ➔ Gives rigidity and protects plant cell ➔ Allows water and dissolved materials to pass through easily thanks to pores ➔ Contains cellulose (dietary fibre) Cytoplasm ➔ Gel-like substance (cytosol) that holds the organelles, sugar and water (life-supporting material) ➔ Fills interior of the cell Nucleus ➔ Controls cell activities (a.k.a. the brain of the cell) ➔ Surrounded by nuclear envelope made of 2 membranes which fuse to form pores and control the passage of substances in/out of nucleus ➔ Contains most of the cells DNA as chromatin (uncoiled DNA and proteins) ➔ Contains nucleolus Nucleolus ➔ Site of ribosome synthesis and assembly Ribosomes ➔ Site of protein synthesis (protein is necessary for a cell’s structure and activities necessary for survival) ➔ Float free in cytoplasm or cling to rough endoplasmic reticulum Rough ➔ Rough: Contains ribosomes which produce proteins Endoplasmic ➔ Canals transport fat and protein to other locations within the cell, including the Reticulum (RER) golgi apparatus. Smooth ➔ Smooth: produces fats (lipids) Endoplasmic ➔ Canals transport fat and protein to other locations within the cell, including the Reticulum (SER) golgi apparatus ➔ Products of the SER become enclosed in membrane-bound structures called vesicles which then pinch off from the SER and move to golgi apparatus Gogli Apparatus/ Golgi ➔ Processes (modifies), packages, and stores fats and proteins produced by the ER Body ➔ Located in the cytoplasm near ER ➔ Exports proteins and fats to new locations within the cell or sends them to the cell’s surface Mitochondria ➔ Powerhouse of the cell ➔ Provides energy for the cell [cellular respiration →produces ATP (main source of energy in cells)] Vacuoles ➔ Store materials: water, starch and fats ➔ Formed from pieces of membrane that have broken loose from the cell membrane, vacules golgi apparatus or ER Microtubules ➔ Long, hollow, cylindrical structures in the cytoplasm made of protein ➔ Give some shape and rigidity to the cell ➔ Form cilia and flagella (used for locomotion of the cell) Microfilaments ➔ Long, thread-like strands of protein found in some cells ➔ Associated with cell movement (muscle contraction in large organisms) Plastids ➔ 3 main types Leucoplasts- store starch granules Chromoplasts- store pigment molecules Chloroplasts- site for photosynthesis ➔ Has its own type of DNA in plant cells but not the main source (nucleus) Chloroplasts ➔ Contain chlorophyll (green pigment that absorbs light to provide energy for photosynthesis and carbohydrate production) ➔ Produces food for plants Lysosomes ➔ Digest, destroy and clean-out cells: “Garbage Men” ➔ Contain digestive enzymes that break down large molecules stored in vacuoles (fats and proteins) into smaller constituents to be oxidized by enzymes of the mitochondria. ➔ Enzymes also break down destructive cells (i.e. bacteria), cells and tissues no longer necessary for the organism’s development (i.e. cells that form tadpole tales) Centriole ➔ Composed of microtubules ➔ Found in pairs- in cell division, separate and move towards opposite ends of the cell and radiate microtubules (arranging themselves in the shape of a football or spindle that spans the cell to aid in the movement of chromosomes during cell division) ➔ The pair is inside the centrosome Cell theory Historical Background: ○ Robert Hooke (1665): First person to study cells using a microscope he built himself. ○ Microscopy advancements (1860-1870) led to the discovery of cells and enhanced disease treatment. Three Main Principles: 1. All living organisms are made of one or more cells. 2. The cell is the basic organizational unit of life. 3. All cells come from pre-existing cells. Microscopes Microscopy: ↳The science of using microscopes to view tiny samples and objects. Microscope Parts: Eyepiece/Ocular Lens: The part you look through. Tube: Connects the eyepiece to the objective lenses. Coarse Adjustment Knob: Brings the specimen into general focus. Fine Adjustment Knob: Sharpens the focus of the specimen. Revolving Nose Piece: Holds and allows selection of objective lenses. Objective Lenses: Magnify the specimen (e.g., 4x, 10x, 40x). Arm: Supports the tube and connects to the base. Stage: Platform where the slide is placed. Stage Clips: Hold the slide in place. Iris Diaphragm: Adjusts the amount of light reaching the specimen. Condenser Lens: Focuses light on the specimen. Light Source/Illuminator: Provides the light needed to view the specimen. Base: Supports the microscope. Magnification and Resolution: Magnification: Increases the size of the specimen's image. Total Magnification = Eyepiece Lens Magnification × Objective Lens Magnification. ⤷ Ex. 10x (eyepiece) × 40x (objective) = 400x total magnification. Resolution: Ability to distinguish two close objects as separate. ⤷ Ex. Resolution of 0.2 microns means objects must be 0.2 microns apart to be seen as distinct. Types of Microscopes: Light Microscopes: Use light to view specimens. ○ Brightfield: Dark image on a light background. ○ Darkfield: Light image on a dark background. ○ Phase-Contrast: Detailed image of living specimens without stain. Electron Microscopes: Use electron beams to visualize images. ○ Transmission Electron Microscopes (TEMs): Ideal for visualizing internal structures. ○ Scanning Electron Microscopes (SEMs): Ideal for visualizing 3D surfaces. DNA ↳ (Deoxyribonucleic Acid) DNA is a nucleic acid containing genetic instructions for the development and functioning of all known living organisms. ○ Two long polymers of nucleotides with backbones made of deoxyribose sugars and phosphate groups. ○ Organized into chromosomes within the nucleus. ○ Segments called genes. Chromosomes ○ Found in the nucleus. ○ Duplicated during cell division. ○ Determine cell function, lifespan, and structure. ○ Each chromosome has a single DNA molecule divided into genes. Karyotype: ↳A micrograph of chromosomes arranged in pairs. ○ Observes chromosomal composition (number, size, shape). Gens ↳ A gene is a segment of DNA that provides instructions for making a specific protein. → Genes control cell activities and structure by making proteins. ○ Genes vary based on the sequence of adenine (A), thymine (T), cytosine (C), and guanine (G). ○ The sequence determines protein production and organism characteristics. Gene Doping: ↳Altering genes to enhance athletic performance. ○ Provides competitive advantage, harder to detect. Nitrogenous bases (nucleotides) ↳ The source of variation in DNA Components: ○ Purines - Adenine (A), Guanine (G) ○ Pyrimidines - Thymine (T), Cytosine (C) Complementary base pairing: → In a DNA double helix, each type of nucleobase on one strand interacts with only one type on the other strand. A pairs with T. C pairs with G. DNA Screening ↳ Testing for genetic disorders via blood samples or karyotyping. Identifies conditions, assesses disease risks, informs medical decisions. Amniocentesis: ○ Needle insertion through a pregnant woman's abdomen to sample amniotic fluid. → Detects chromosomal abnormalities (e.g., Down syndrome). Blood Tests: ○ Analyzes blood for specific proteins. → Indicates gene function (e.g., PKU detection).  Positive Implications Negative Implications Detects genetic disorders early Causes anxiety for untreatable diseases Allows preventative measures Raises privacy and data misuse concerns Informs family planning decisions Genetic results can be misinterpreted Reduces long-term healthcare costs Advanced screenings can be expensive PKU ↳ Genetic disorder unables you to metabolize phenylalanine. Causes severe brain damage without a special low-protein diet. ○ Aspartame contains phenylalanine, an amino acid found in many proteins Proteins ↳ Each protein has a specific job, and together they ensure the proper functioning of the body. Build/repair tissues, catalyze reactions, transport molecules, signal communication. Protein Imbalances ○ Disrupts body functions (e.g., digestion, material transport, signal transfer). ○ Leads to health issues (e.g., digestive problems, developmental disorders) Mutation ↳ A mutation is a change in the DNA of an organism. Osmosis and Diffusion → The cell membrane is selectively permeable, allowing certain substances to pass through while blocking others. Diffusion ○ The process by which particles move from an area of high concentration to an area of low concentration, eventually reaching equilibrium. Ex. Oxygen (O2) diffuses into cells, and carbon dioxide (CO2) diffuses out. Osmosis ○ The movement of water molecules through a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration. Types of Solutions: Hypertonic Solution ○ Higher solute concentration outside the cell. ○ Water exits the cell, causing it to shrink. Hypotonic Solution ○ Lower solute concentration outside the cell. ○ Water enters the cell, causing it to swell and potentially burst. Isotonic Solution ○ Equal solute concentration inside and outside the cell. ○ No net movement of water; the cell remains the same size. Vaccinations → Vaccination: Administering a vaccine to help the immune system develop protection from a disease. → Immunization: The process by which a person becomes protected against a disease through vaccination. Types Live Attenuated Vaccines: Contain a weakened form of the live pathogen, providing long-lasting immunity. Ex. Measles, Mumps, and Rubella (MMR) vaccine. Inactivated Vaccines: Contain killed or inactivated pathogens, often requiring multiple doses. Ex. Polio vaccine. Subunit/Conjugate Vaccines: Contain specific pieces of the pathogen, allowing the immune system to respond without being exposed to the entire organism. Ex. HPV vaccine. How vaccination works: ○ Vaccination introduces a harmless component of a pathogen into the body, stimulating the immune system to recognize and remember the pathogen without causing illness. ○ If the vaccinated person is later exposed to the actual pathogen, their immune system can recognize and combat it more effectively, preventing disease. Herd immunity: ○ Herd immunity occurs when a significant portion of a population becomes immune to a disease, either through vaccination or previous infection, reducing the spread of the disease and protecting those who are not immune. Human Papillomavirus (HPV): ↳ HPV is a non-enveloped DNA virus that infects cells of the skin and mucous membranes. ➔ It can cause genital warts and several types of cancer. Immunization significantly reduces the risk of developing HPV-related cancers and genital warts. Misconceptions 1. Vaccines do not overload a child's immune system; delaying vaccines increases the risk of disease. 2. Vaccinations are still necessary to prevent diseases from being reintroduced. 3. During outbreaks, vaccinated individuals might outnumber unvaccinated ones among the sick because more people are vaccinated, not because vaccines are ineffective. Fun Facts ○ Chickenpox parties are risky and not recommended. ○ Annual flu vaccines are needed due to changing flu strains. ○ The polio vaccine is not linked to HIV or cancer. ○ Multiple vaccines in childhood schedules protect against serious illnesses. ○ Individual immune responses vary, but most vaccines have high effectiveness rates. Smallpox Symptoms: Fever, lethargy, headache, sore throat, vomiting, rash, fluid-filled pustules, scabs. Transmission: Close contact with sores, respiratory droplets, contaminated bedding or clothing. Edward Jenner: Introduced the concept of vaccination using cowpox to protect against smallpox. WHO Eradication Efforts: Intensive global vaccination campaigns led to the eradication of smallpox in 1980. Polio Symptoms: Asymptomatic, mild illness (abortive polio), neurological symptoms (non-paralytic polio), paralysis (paralytic polio). Transmission: Person-to-person contact, nasal and oral secretions, contaminated feces. Jonas Salk: Developed the first successful polio vaccine. Iron Lung: Provided breathing support for polio victims with paralyzed chest muscles. Ontario Public Health Vaccinations for School Age Children: Ages 4-6 → Tetanus, diphtheria, pertussis, polio, measles, mumps, rubella, chicken pox. Grade 7 → Meningococcal conjugate (Men-C-ACYW), hepatitis B, human papillomavirus (HPV). Ages 14-16 → Tetanus, diphtheria, and pertussis. Hepatitis B Transmission: Spread through contact with blood and body fluids of an infected person. Symptoms: Stomach pain, fever, joint pain, loss of appetite, nausea, vomiting, weakness, dark-colored urine, jaundice.