Search for Mushrooms

🦠 MICROBIOLOGY — WEEK 1 STUDY NOTES Microbiology Foundations Assigned reading: 1.1 What Our Ancestors Knew 1.2 A Systematic Approach 1.3 Types of Microorganisms 3.1 Spontaneous Generation 3.2 Foundations of Modern Cell Theor/y 1.1 What Our Ancestors Knew First: What is microbiology? Microbiology = the study of very small organisms and infectious agents. Microorganism / microbe = an organism that is generally too small to see without a microscope. Examples include: * Bacteria * Archaea * Fungi such as yeast and molds * Protozoa * Microscopic algae * Some parasites Viruses are also studied in microbiology, although viruses are acellular, meaning they are not made of cells. Important idea Microbes are NOT automatically bad. Many microbes are harmless or helpful. They: * help produce food * live naturally in and on our bodies * help ecosystems function * can be used to make medicines and other products Only some microbes cause disease. 🍞 Humans Used Microbes Before They Knew Microbes Existed Humans were using microorganisms for thousands of years before microscopes existed. One of the biggest examples is: Fermentation Fermentation = microorganisms change sugars/carbohydrates into substances such as: * alcohol * gases * organic acids Microbes involved can include: bacteria + yeast + molds Humans used fermentation to make: * bread * cheese * yogurt * beer * wine * pickled vegetables Easy example Yeast eats/metabolizes carbohydrates in bread dough. ↓ Yeast produces carbon dioxide (CO₂). ↓ Gas becomes trapped in the dough. ↓ Bread rises. Remember Fermentation = microbes changing sugars. ⸻ 🧊 Ötzi the Iceman Ötzi was a preserved human mummy approximately 5,300 years old. Scientists found evidence that he had: * Trichuris trichiura → a parasitic worm * Borrelia burgdorferi → bacterium that causes Lyme disease He also carried a fungus called Fomitopsis betulinus, which has laxative and antibiotic properties. Why does this matter? It shows that ancient people were trying to treat disease long before they understood microorganisms. ⸻ 🦠 Early Ideas About Disease Before microscopes, people didn’t know exactly what caused disease. Some cultures believed disease came from: * supernatural forces * angry gods * fate * bad air But some people began to realize that disease might spread between people. ⸻ Quarantine Ancient societies sometimes separated sick people from healthy people. This is called: Quarantine = separating potentially infected people to prevent disease spread. Even though they didn’t know what bacteria or viruses were, they understood that some diseases could spread. ⸻ 🚿 Sanitation Ancient civilizations also developed ways to improve sanitation. Examples included: * clean-water systems * drainage systems * sewers * aqueducts This was important because removing human waste and providing cleaner water can reduce disease transmission. ⸻ Important People From Early Medicine Hippocrates Who? Greek physician. Important idea: Disease had natural causes, rather than always being caused by supernatural forces. He is commonly called: “Father of Western Medicine.” Remember Hippocrates → disease has natural causes. ⸻ Thucydides Thucydides survived the Athenian plague. He noticed that people who survived the disease usually did not become sick from the same disease again while caring for infected people. This was an early observation of: Immunity Immunity = the body’s ability to resist a particular infection/disease. Remember Thucydides → early idea of immunity. ⸻ Marcus Terentius Varro Varro proposed that extremely tiny creatures that could not be seen might cause disease. He described tiny creatures entering the body through the: * mouth * nose This was an important idea because microscopes did not yet exist. Remember Varro → invisible tiny creatures may cause disease. ⸻ Ibn Sina / Avicenna Ibn Sina wrote the important medical work: Canon of Medicine He described ideas involving: * contagion * spread of disease * transmission through breath * isolation of sick people His work contributed to ideas that later became important for quarantine and infectious-disease control. ⸻ 🔬 Birth of Microbiology The development of the microscope completely changed science. For the first time, scientists could actually see microorganisms. ⸻ Antonie van Leeuwenhoek Extremely important name. In 1675, Antonie van Leeuwenhoek used powerful simple microscopes to observe tiny organisms. He called them: “animalcules” Today we know that some of the organisms he observed were: * bacteria * protists Remember Leeuwenhoek → first to describe bacteria/microorganisms seen through a microscope. Think: Leeuwenhoek = LOOKED at microbes. ⸻ ⭐ Golden Age of Microbiology Approximately: 1857–1914 During this period, scientists made major discoveries connecting microorganisms with: * fermentation * disease * medicine * infection Two huge names: Louis Pasteur and Robert Koch You are going to see both names repeatedly in microbiology. ⸻ Louis Pasteur Pasteur showed that microorganisms are responsible for fermentation. He also developed: Pasteurization Pasteurization = using controlled heat to kill/reduce microorganisms that cause spoilage or disease. He also worked on vaccines, including a vaccine against: rabies Pasteur will become especially important again in Section 3.1. Remember Pasteur → fermentation → pasteurization → vaccines → helped prove germ theory → disproved spontaneous generation ⸻ Robert Koch Koch showed that particular microbes could cause particular diseases. He identified microorganisms associated with diseases including: * anthrax * tuberculosis * cholera Remember Koch → specific microbe → specific disease. ⸻ 🧪 Basic Microbiology Laboratory Tools You don’t need to master these yet, but recognize the terms. Microscope → magnifies microbes. Stains/dyes → add color/contrast so microorganisms are easier to see. Growth media → nutrients/material used to grow microorganisms in the laboratory. Petri dish → shallow dish commonly used to hold growth media. Test tube → can contain liquid or solid/semi-solid growth media. Bunsen burner → flame that can be used during laboratory sterilization procedures. These will make much more sense once you start doing microbiology lab work. ⸻ 1.2 A Systematic Approach Now we move from discovering microbes to: “How do scientists organize and name all these different organisms?” ⸻ Taxonomy Definition Taxonomy = classification, description, identification, and naming of living organisms. Think: Taxonomy = biological organization system. ⸻ Carolus Linnaeus Linnaeus developed an important system for classifying organisms. The main levels used in classification include: Kingdom → Phylum → Class → Order → Family → Genus → Species A common memory trick: K P C O F G S King Philip Came Over For Good Soup You should know the order. ⸻ Species Species is the most specific/basic taxonomic level in this hierarchy. Example: Homo sapiens Homo = genus sapiens = species ⸻ Binomial Nomenclature Very important term. Binomial = two names. Every organism receives a scientific name consisting of: Genus + species Example: Homo sapiens Rules: Genus * first letter CAPITALIZED species * lowercase Both should normally be italicized when typed. Correct: Homo sapiens Not: Homo Sapiens ❌ homo sapiens ❌ Homo Sapiens ❌ ⸻ 🌳 Phylogeny Phylogeny = evolutionary relationship/history between organisms. Scientists can represent these relationships with a: Phylogenetic tree A phylogenetic tree shows how organisms are believed to be evolutionarily related. Organisms with a more recent common ancestor are considered more closely related. ⸻ Classification Changed Over Time Scientific classification did not stay the same. Linnaeus Originally divided nature into kingdoms including: * animals * plants * minerals The mineral kingdom was later abandoned. ⸻ Ernst Haeckel Added: Protista for many unicellular organisms. He later proposed Monera for organisms lacking nuclei. Remember: Haeckel → Protista ⸻ Robert Whittaker Developed a five-kingdom system: Animalia Plantae Fungi Protista Monera ⸻ 🧬 Carl Woese — VERY IMPORTANT Carl Woese used differences in: ribosomal RNA (rRNA) to study evolutionary relationships. His work helped establish the modern: THREE-DOMAIN SYSTEM 🟠 Bacteria 🟣 Archaea 🔵 Eukarya This is very important for your Week 1 material. Memorize: BAE Bacteria Archaea Eukarya ⸻ Bergey’s Manuals These are important references used in bacteriology. They help scientists: * classify bacteria * identify bacteria You probably don’t need every detail yet, but recognize the name: Bergey’s Manual ⸻ How Can Bacteria Be Identified? Scientists can identify microorganisms using things such as: Biochemical tests Look at chemical/metabolic characteristics. DNA/RNA analysis Examines genetic material. Serological tests Use reactions involving antibodies/antigens. ⸻ 1.3 Types of Microorganisms This section is VERY IMPORTANT. You need to understand the major groups. ⸻ 🌎 Three Domains of Life Again: 1. Bacteria 2. Archaea 3. Eukarya ⸻ Before We Continue: Two Big Cell Types You will hear these words constantly: PROKARYOTE vs EUKARYOTE Prokaryotic cells DO NOT have a membrane-bound nucleus. Bacteria = prokaryotic Archaea = prokaryotic Eukaryotic cells DO have a membrane-bound nucleus. Examples include: * animals * plants * fungi * protozoa * algae Super important: Prokaryote = NO nucleus Eukaryote = HAS nucleus ⸻ 🦠 BACTERIA Bacteria are: * unicellular * prokaryotic * found almost everywhere Some bacteria are helpful. Some bacteria can cause disease. Many bacteria have cell walls. You’ll learn much more about bacterial structures later. ⸻ 🌋 ARCHAEA Archaea are also: * unicellular * prokaryotic Like bacteria, they do not have a nucleus. BUT: Archaea ≠ Bacteria They differ in: * genetics * evolutionary history * metabolic pathways * cell membrane composition * cell wall composition Archaea occur in many environments. Important textbook point No archaea have been identified as human pathogens. Remember Bacteria + Archaea = Prokaryotes ⸻ 🔵 EUKARYA Eukaryotic microorganisms include: Algae Protozoa Fungi Helminths These have eukaryotic cells. ⸻ 🌿 ALGAE Algae can be: * unicellular * multicellular They are similar to plants in an important way: They perform photosynthesis. Photosynthesis = using light energy to make chemical energy/food. Remember: Algae → photosynthesis. ⸻ 🧫 PROTOZOA Protozoa are: * unicellular * eukaryotic * structurally more complex than bacteria Many are capable of movement. Remember Protozoa → single-celled eukaryotes, often motile. Motile = able to move. ⸻ 🍄 FUNGI Fungi studied in microbiology include: Yeasts Usually unicellular. Molds Usually grow as multicellular filament-like structures. Examples of fungi can be microscopic even though other fungi, such as mushrooms, are large. Remember Fungi → yeast + molds ⸻ 🪱 HELMINTHS Helminths = parasitic worms. You may think: “A worm isn’t microscopic. Why is it in microbiology?” Good question. Adult worms may be large enough to see. BUT their: * eggs * larvae can be microscopic. Therefore they are studied in microbiology. ⸻ 🦠 VIRUSES Viruses are different from cellular organisms. Viruses are ACELLULAR. Acellular = not made of cells. Viruses cannot reproduce independently. They require a: Host cell to reproduce. Remember Virus = acellular + requires host to reproduce ⸻ ⭐ Major Microorganism Comparison Group Cell type Nucleus? Important idea Bacteria Prokaryotic ❌ Some cause disease Archaea Prokaryotic ❌ Different from bacteria; no known human pathogens Fungi Eukaryotic ✅ Yeasts + molds Protozoa Eukaryotic ✅ Unicellular, often motile Algae Eukaryotic ✅ Photosynthesis Helminths Eukaryotic ✅ Parasitic worms Viruses Acellular No cell Need host to reproduce 🔥 This table is worth knowing very well. ⸻ 3.1 Spontaneous Generation This is mainly about one historical question: Where does life come from? People once believed: Spontaneous Generation Spontaneous generation = the belief that living organisms can arise from nonliving material. Examples people once believed: rotting meat → maggots mud → frogs old food → microorganisms Today we know this idea is incorrect. ⸻ Francesco Redi Redi tested whether maggots appeared spontaneously from meat. He compared meat that flies could reach with meat protected from flies. Result Maggots appeared when flies could access the meat. This suggested: Maggots came from flies — not directly from the meat. Remember Redi → meat + flies + maggots ⸻ John Needham Needham performed experiments with broth. He boiled broth and then observed microbial growth afterward. He interpreted this as evidence supporting: Spontaneous generation. Remember Needham → supported spontaneous generation. ⸻ Lazzaro Spallanzani Spallanzani disagreed. He boiled broth for longer and sealed the containers more carefully. The sealed broth did not show microbial growth. He argued that microbes came from contamination from the environment rather than being generated spontaneously. Remember Spallanzani → argued against spontaneous generation. ⸻ 🦢 Louis Pasteur’s Swan-Neck Flask Experiment This is VERY IMPORTANT. Pasteur used flasks with long curved necks. Why the curved neck? Air could enter the flask. BUT: Dust and microorganisms became trapped in the curved neck. So the broth remained uncontaminated. When microorganisms could reach the broth, microbial growth occurred. Conclusion Microorganisms did NOT spontaneously appear. They came from microorganisms already present in the environment. Pasteur helped establish the principle: “Life comes from life.” Exam memory Pasteur → swan-neck flask → disproved spontaneous generation. ⸻ 3.2 Foundations of Modern Cell Theory Now we move from: “Where do microbes come from?” to: “What is life made of?” Answer: CELLS ⸻ 🧬 Cell Theory The textbook describes the development of the idea that cells are the fundamental units of life. The central ideas are: 1. All living organisms are made of one or more cells. 2. The cell is the fundamental/basic unit of life. 3. Cells arise from pre-existing cells. Think: Life → cells → cells come from cells. ⸻ Robert Hooke In the 1660s, Robert Hooke examined cork with a microscope. He saw tiny compartments and called them: “cells” Remember Hooke → named/described cells. Don’t mix him up with Leeuwenhoek: Hooke → cells Leeuwenhoek → microorganisms ⸻ Matthias Schleiden Schleiden studied plants. He concluded that: Plants are made of cells. Remember: Schleiden → plants ⸻ Theodor Schwann Schwann studied animals. He concluded: Animals are made of cells. Remember: Schwann → animals ⸻ Robert Remak Remak provided evidence that cells form through the division of existing cells. ⸻ Rudolf Virchow Virchow strongly promoted the idea: Cells come from other cells. So: New cells do not spontaneously appear. ⸻ Easy Scientist Memory Hooke → saw/named cells Schleiden → plants Schwann → animals Remak/Virchow → cells come from existing cells ⸻ 🧬 Endosymbiotic Theory This sounds difficult, but the basic idea is simple. Endosymbiotic theory says: Mitochondria and chloroplasts were originally bacteria-like prokaryotic cells. A larger ancestral cell engulfed them. Instead of being destroyed, the cells developed a mutually beneficial relationship. Eventually, the engulfed bacteria evolved into: Mitochondria and Chloroplasts inside eukaryotic cells. ⸻ Evidence for Endosymbiotic Theory Mitochondria and chloroplasts have similarities to bacteria. They have: Their own DNA Their DNA resembles bacterial DNA. Their own ribosomes Their ribosomes resemble bacterial ribosomes. They reproduce through a process similar to binary fission Binary fission is a major way bacteria reproduce. Easy version Mitochondria and chloroplasts act strangely like bacteria because their ancestors were bacteria. ⸻ Lynn Margulis Lynn Margulis helped develop and promote the modern endosymbiotic theory. Remember Margulis → endosymbiotic theory ⸻ 🦠 Miasma Theory vs Germ Theory This distinction is very important. Miasma Theory Old idea: Disease comes from “bad air” associated with rotting material. Think: Bad smell → disease. This theory was eventually replaced. ⸻ Germ Theory Germ theory = many diseases are caused by microorganisms. Think: Microbe enters/infects body → disease Scientists whose work helped establish germ theory included: * Ignaz Semmelweis * John Snow * Louis Pasteur * Joseph Lister * Robert Koch ⸻ 🧼 Ignaz Semmelweis Semmelweis worked around childbirth. He noticed that patients treated by doctors and medical students had much higher rates of puerperal fever than patients cared for by midwives. Medical students often went from: autopsies → examining living patients without washing their hands. Semmelweis introduced handwashing with chlorinated lime solution. Result Maternal deaths fell dramatically. Remember Semmelweis → HANDWASHING ⸻ 💧 John Snow John Snow investigated cholera outbreaks in London. He connected cholera cases with: contaminated water. His work helped show that disease wasn’t simply coming from “bad air.” He is important in the history of: Epidemiology Epidemiology = study of disease patterns and spread in populations. Remember Snow → cholera + contaminated water + epidemiology ⸻ Joseph Lister Lister applied ideas about microorganisms to surgery. He promoted: * handwashing * cleanliness * sterilization * antiseptic techniques He used carbolic acid (phenol) to reduce infections during surgery. Result Surgical infections decreased. Remember Lister → antiseptic surgery ⸻ Robert Koch — Again Koch developed: Koch’s postulates These helped scientists determine whether a particular microorganism causes a particular disease. Basic idea: specific microorganism → specific disease You will learn Koch’s postulates in more detail later. ⸻ 🔥 WEEK 1 — PEOPLE YOU NEED TO KNOW Scientist/person Remember THIS Hippocrates Disease has natural causes Thucydides Early observation of immunity Varro Invisible creatures may cause disease Leeuwenhoek Observed microbes/bacteria Linnaeus Taxonomy + naming organisms Haeckel Added Protista Whittaker Five kingdoms Woese Three domains; used rRNA Redi Meat + flies + maggots Needham Supported spontaneous generation Spallanzani Evidence against spontaneous generation Pasteur Swan-neck flask; fermentation; germ theory Hooke Described/named cells Schleiden Plants are made of cells Schwann Animals are made of cells Remak/Virchow Cells come from cells Margulis Endosymbiotic theory Semmelweis Handwashing John Snow Cholera + contaminated water Lister Antiseptic surgery Koch Specific microbes cause specific diseases ⸻ 🚨 THE 15 THINGS I WOULD MEMORIZE FIRST Don’t try to memorize every paragraph tonight. Start here: 1. Microbiology = study of microorganisms. 2. Fermentation uses microbes to convert sugars into products such as alcohol, gases, or acids. 3. Leeuwenhoek observed microorganisms. 4. Pasteur and Koch were major scientists during the Golden Age of Microbiology. 5. Taxonomy = classification and naming of organisms. 6. Binomial nomenclature = Genus + species. 7. Three domains = Bacteria, Archaea, Eukarya. 8. Bacteria + Archaea = prokaryotes. 9. Prokaryote = no membrane-bound nucleus. 10. Eukaryote = has membrane-bound nucleus. 11. Virus = acellular and needs a host to reproduce. 12. Spontaneous generation = life arises from nonliving matter. 13. Pasteur’s swan-neck flask helped disprove spontaneous generation. 14. Cell theory = organisms are made of cells, cells are the basic unit of life, and cells come from existing cells. 15. Germ theory = microorganisms can cause disease. ⸻ 🧠 Super-Simple Week 1 Mental Map Think about the entire week’s reading as one story: PART 1 — Humans discover microbes People used microbes before knowing they existed. ↓ Leeuwenhoek sees them. ↓ Scientists begin studying them. ⸻ PART 2 — Scientists organize microbes Linnaeus → Taxonomy ↓ Woese → 3 domains ↓ Bacteria | Archaea | Eukarya ⸻ PART 3 — Scientists ask where life comes from People believed in spontaneous generation. ↓ Redi + Spallanzani question it. ↓ Pasteur disproves it. ↓ Life comes from existing life. ⸻ PART 4 — Scientists understand cells Hooke → cells ↓ Schleiden → plants Schwann → animals ↓ Remak/Virchow → cells come from cells ↓ Cell Theory ⸻ PART 5 — Scientists understand disease Old: Miasma = bad air causes disease ❌ ↓ New: Germ theory = microorganisms can cause disease ✅ ↓ Semmelweis → handwashing Snow → contaminated water Lister → antiseptic surgery Pasteur → microbes Koch → specific microbe causes specific disease

bio Genetics is the study of heredity and how traits are passed from parents to offspring. Gregor Mendel is known as the “Father of Genetics.” Why did Mendel use pea plants? * Easy to grow * Short generation time * Many visible traits * Can self-pollinate or cross-pollinate * Produce many offspring Examples of traits studied: * Flower colour * Seed shape * Plant height ⸻ VOCABULARY Gene * A segment of DNA that controls a trait. Allele * Different forms of the same gene. Example: P = purple flowers p = white flowers Dominant Allele * Expressed whenever it is present. * Represented by a capital letter. Example: P = purple Recessive Allele * Only expressed when two copies are present. * Represented by a lowercase letter. Example: p = white Genotype * Genetic makeup of an organism. Examples: PP Pp pp Phenotype * Physical appearance of an organism. Examples: Purple flower White flower Homozygous * Two identical alleles. Examples: PP pp Heterozygous * Two different alleles. Example: Pp Pure Breeding * Homozygous for a trait. Gamete * Sex cell (sperm or egg). ⸻ MENDEL’S LAWS Law of Dominance * A dominant allele masks a recessive allele. Example: Pp = Purple flower Law of Segregation * Alleles separate during gamete formation. * Each gamete receives only one allele. Example: Parent = Pp Gametes: P p Law of Independent Assortment * Different genes assort independently during meiosis. ⸻ MONOHYBRID CROSSES A monohybrid cross studies one trait. Example: P = Purple p = White Cross: Pp × Pp Punnett Square INCOMPLETE DOMINANCE Neither allele completely dominates. Example: Snapdragons RR = Red WW = White RW = Pink Cross: RW × RW Genotype Ratio: 1 RR : 2 RW : 1 WW Phenotype Ratio: 1 Red : 2 Pink : 1 White CODOMINANCE Both alleles are expressed equally. Example: AB Blood Type Genotype: IAIB Phenotype: AB MULTIPLE ALLELES More than two alleles exist in a population. Example: ABO Blood Group Alleles: IA IB i BLOOD TYPES Type A Genotypes: IAIA or IAi Type B Genotypes: IBIB or IBi Type AB Genotype: IAIB Type O Genotype: ii Can Type A and Type B Parents Have a Type O Child? Yes. If: Father = IAi Mother = IBi Possible Blood Types: AB A B O CELL CYCLE Purpose: * Growth * Repair * Replacement of cells Stages: G1 S G2 Mitosis Cytokinesis INTERPHASE G1 Phase Cell grows and carries out normal functions. S Phase DNA replication occurs. G2 Phase Cell prepares for division. MITOSIS Purpose: Growth and repair. Produces: 2 genetically identical diploid cells. PROPHASE Events: * Chromosomes condense * Nuclear membrane disappears * Nucleolus disappears * Spindle fibres form METAPHASE Events: * Chromosomes line up at the equator ANAPHASE Events: * Sister chromatids separate TELOPHASE Events: * Nuclear membranes reform * Chromosomes uncoil CYTOKINESIS Division of the cytoplasm. Animal Cells: Cleavage furrow forms. Plant Cells: Cell plate forms. CHROMOSOME STRUCTURE Chromosome consists of: * Two sister chromatids * One centromere DIPLOID VS HAPLOID Diploid (2n) * Two sets of chromosomes * Human body cells * 46 chromosomes Haploid (n) * One set of chromosomes * Human gametes * 23 chromosomes HOMOLOGOUS CHROMOSOMES Chromosome pairs that: * Carry the same genes * One comes from the mother * One comes from the father Humans have 23 homologous pairs. MEIOSIS Purpose: Produce gametes. Produces: 4 genetically unique haploid cells. MEIOSIS I Separates homologous chromosomes. CROSSING OVER Occurs during Prophase I. Definition: Exchange of DNA between homologous chromosomes. Importance: Creates genetic variation. RANDOM ASSORTMENT Occurs during Metaphase I. Definition: Homologous pairs line up randomly. Importance: Creates unique chromosome combinations. MEIOSIS II Separates sister chromatids. MITOSIS VS MEIOSIS Mitosis * 2 cells produced * Diploid * Genetically identical * Growth and repair Meiosis * 4 cells produced * Haploid * Genetically different * Produces gametes NONDISJUNCTION Failure of chromosomes to separate properly during meiosis. Can result in extra or missing chromosomes. DOWN SYNDROME Cause: Extra chromosome 21. Chromosome Number: 47 Usually caused by nondisjunction during meiosis. DNA DNA = Deoxyribonucleic Acid Shape: Double Helix Function: Stores genetic information. NUCLEOTIDE Three Components: * Phosphate Group * Deoxyribose Sugar * Nitrogenous Base NITROGENOUS BASES Adenine (A) Thymine (T) Cytosine (C) Guanine (G) COMPLEMENTARY BASE PAIRING A pairs with T C pairs with G DNA REPLICATION Purpose: Make identical copies of DNA. Location: Nucleus Result: Two identical DNA molecules. TRANSCRIPTION Purpose: Create mRNA from DNA. Location: Nucleus DNA → mRNA Remember: RNA uses Uracil (U) instead of Thymine (T). TRANSLATION Purpose: Make proteins. Location: Ribosome mRNA is read and amino acids are joined together to form a protein. MUTATIONS A mutation is a change in DNA sequence. Types: * Deletion * Duplication * Inversion * Translocation DELETION DNA segment removed. DUPLICATION DNA segment repeated. INVERSION DNA segment reversed. TRANSLOCATION DNA segment moves to another chromosome. SEX-LINKED TRAITS Traits located on sex chromosomes. Most are located on the X chromosome. RED-GREEN COLOUR BLINDNESS Inheritance: X-linked recessive. XC = Normal Vision Xc = Colour Blind Male: XcY Colour blind boys inherit the allele from their mother because fathers pass a Y chromosome to their sons. TAY-SACHS DISEASE Cause: Missing enzyme that breaks down lipids in nerve cells. Inheritance: Autosomal recessive. Treatment: No cure currently available. SICKLE CELL ANEMIA Cause: Mutation in hemoglobin gene. Effects: * Sickle-shaped red blood cells * Reduced oxygen transport * Blocked blood vessels Inheritance: Autosomal recessive. HUNTINGTON’S DISEASE Cause: Dominant mutation. Effects: * Nervous system degeneration * Loss of motor control * Cognitive decline Inheritance: Autosomal dominant. KARYOTYPE A photograph of chromosomes arranged in pairs. Used to: * Determine sex * Detect chromosome abnormalities * Diagnose genetic disorders PEDIGREE A family tree used to track inheritance patterns. Symbols: Square = Male Circle = Female Shaded = Has trait CLONING Producing genetically identical organisms. Uses: * Research * Agriculture * Medicine * Conservation GENETIC COUNSELLING Provides information about: * Inherited disorders * Family risk * Testing options AMNIOCENTESIS Prenatal test in which amniotic fluid is sampled and fetal cells are analyzed. Can detect: * Genetic disorders * Chromosomal disorders GMOs Genetically Modified Organisms. Definition: Organisms whose DNA has been altered through biotechnology. Advantages: * Increased crop yield * Disease resistance * Pest resistance Disadvantages: * Ethical concerns * Environmental concerns DNA REPLICATION → TRANSCRIPTION → TRANSLATION DNA (Nucleus) ↓ Replication DNA Copy DNA ↓ Transcription mRNA mRNA ↓ Translation Protein Final Product: Protein RESPIRATORY SYSTEM Function: * Brings oxygen into the body * Removes carbon dioxide * Works with the circulatory system to supply cells with oxygen Why do organisms require oxygen and produce carbon dioxide? Oxygen is required for cellular respiration. Cellular Respiration: Glucose + Oxygen → Energy (ATP) + Carbon Dioxide + Water Cells use oxygen to release energy from food. Carbon dioxide is produced as a waste product and must be removed. ⸻ PATHWAY OF AIR Nasal Cavity ↓ Pharynx ↓ Larynx ↓ Trachea ↓ Bronchi ↓ Bronchioles ↓ Alveoli ⸻ NASAL CAVITY Functions: * Warms air * Moistens air * Filters air Nasal Hairs: * Trap large particles Mucus: * Traps dust and microorganisms Blood Capillaries: * Warm incoming air ⸻ PHARYNX Common passageway for: * Air * Food Also called the throat. ⸻ UVULA Functions: * Prevents food from entering nasal cavity * Helps with speech ⸻ EPIGLOTTIS Functions: * Covers trachea during swallowing * Prevents choking ⸻ LARYNX Also called the voice box. Contains vocal cords. ⸻ TRACHEA Also called the windpipe. Contains cartilage rings that prevent collapse. Lined with: * Cilia * Mucus ⸻ CILIA Tiny hair-like structures. Function: * Sweep mucus upward toward throat ⸻ BRONCHI Two branches of the trachea leading to lungs. Right Bronchus → Right Lung Left Bronchus → Left Lung ⸻ BRONCHIOLES Smaller branches inside lungs. Lead to alveoli. ⸻ ALVEOLI Tiny air sacs. Site of gas exchange. Adaptations: * Thin walls * Moist surface * Large surface area * Rich blood supply Gas Exchange: Oxygen moves: Alveoli → Blood Carbon Dioxide moves: Blood → Alveoli By diffusion. ⸻ BREATHING MECHANICS Two main muscles: 1. Diaphragm 2. Intercostal Muscles ⸻ INHALATION (INSPIRATION) Diaphragm: * Contracts * Moves downward Intercostal Muscles: * Contract * Lift ribs upward Result: * Chest cavity volume increases * Pressure decreases * Air enters lungs ⸻ EXHALATION (EXPIRATION) Diaphragm: * Relaxes * Moves upward Intercostal Muscles: * Relax Result: * Chest cavity volume decreases * Pressure increases * Air leaves lungs ⸻ MEDULLA OBLONGATA Located in the brainstem. Function: * Controls breathing rate Responds to: * Carbon dioxide levels More CO₂: * Faster breathing Less CO₂: * Slower breathing ⸻ LUNG VOLUMES Tidal Volume * Normal amount of air breathed in and out Inspiratory Reserve Volume * Extra air inhaled after normal breath Expiratory Reserve Volume * Extra air exhaled after normal breath Residual Volume * Air remaining in lungs after maximum exhalation Vital Capacity * Maximum amount of air exhaled after deepest breath Total Lung Capacity * Total amount of air lungs can hold ⸻ CIRCULATORY SYSTEM Functions: * Transport oxygen * Transport nutrients * Remove wastes * Maintain homeostasis * Transport hormones Humans have a CLOSED circulatory system. Blood remains inside vessels. ⸻ BLOOD VESSELS ARTERIES Function: * Carry blood away from heart Characteristics: * Thick walls * High pressure * Small lumen * No valves Usually oxygen-rich Exception: Pulmonary artery ⸻ VEINS Function: * Carry blood toward heart Characteristics: * Thin walls * Low pressure * Large lumen * Valves present Usually oxygen-poor Exception: Pulmonary vein ⸻ CAPILLARIES Smallest blood vessels. Functions: * Gas exchange * Nutrient exchange * Waste exchange Walls are one cell thick. ⸻ HEART STRUCTURE Blood Flow: Body ↓ Vena Cava ↓ Right Atrium ↓ Right Ventricle ↓ Pulmonary Artery ↓ Lungs ↓ Pulmonary Vein ↓ Left Atrium ↓ Left Ventricle ↓ Aorta ↓ Body ⸻ HEART CHAMBERS Right Atrium * Receives deoxygenated blood Right Ventricle * Pumps blood to lungs Left Atrium * Receives oxygenated blood Left Ventricle * Pumps blood to body ⸻ SEPTUM Wall separating left and right sides of heart. Prevents mixing of blood. ⸻ HEART VALVES Function: * Prevent backflow of blood Types: Atrioventricular (AV) Valves Pulmonary Semilunar Valve Aortic Semilunar Valve ⸻ SA NODE Sinoatrial Node Known as: * Natural pacemaker Initiates heartbeat. ⸻ AV NODE Atrioventricular Node Receives signal from SA node. Delays impulse slightly. Allows ventricles to fill before contraction. ⸻ BLOOD Components: 1. Plasma 2. Red Blood Cells 3. White Blood Cells 4. Platelets ⸻ PLASMA Liquid component of blood. Functions: * Transport nutrients * Transport hormones * Transport wastes ⸻ RED BLOOD CELLS (ERYTHROCYTES) Function: * Carry oxygen Contain: * Hemoglobin ⸻ HEMOGLOBIN Protein in red blood cells. Function: * Binds oxygen Allows oxygen transport. ⸻ WHITE BLOOD CELLS (LEUKOCYTES) Function: * Fight infection * Defend body Part of immune system. ⸻ PLATELETS Function: * Blood clotting Prevent blood loss. ⸻ BLOOD PRESSURE Force of blood against artery walls. Measured using: Sphygmomanometer Example: 120/80 120 = Systolic Pressure 80 = Diastolic Pressure ⸻ SYSTOLIC PRESSURE Pressure when heart contracts. ⸻ DIASTOLIC PRESSURE Pressure when heart relaxes. ⸻ HYPERTENSION High blood pressure. Can increase risk of: * Stroke * Heart attack * Kidney disease ⸻ STROKE VOLUME Amount of blood pumped per heartbeat. ⸻ CARDIAC OUTPUT Amount of blood pumped per minute. Formula: Cardiac Output = Heart Rate × Stroke Volume ⸻ ECG Electrocardiogram Measures electrical activity of heart. Used to detect: * Irregular heartbeat * Heart damage ⸻ PULMONARY CIRCULATION Heart → Lungs → Heart Purpose: * Oxygenate blood ⸻ SYSTEMIC CIRCULATION Heart → Body → Heart Purpose: * Deliver oxygen to tissues ⸻ HOMEOSTASIS DURING EXERCISE Body responds by: * Increasing heart rate * Increasing breathing rate * Increasing cardiac output * Redirecting blood to muscles * Sweating to cool body Purpose: Maintain stable internal conditions. ⸻ DIGESTIVE SYSTEM Functions: * Break down food * Absorb nutrients * Eliminate waste ⸻ DIGESTIVE TRACT Mouth ↓ Pharynx ↓ Esophagus ↓ Stomach ↓ Small Intestine ↓ Large Intestine ↓ Rectum ↓ Anus ⸻ MECHANICAL DIGESTION Physical breakdown of food. Examples: * Chewing * Churning ⸻ CHEMICAL DIGESTION Chemical breakdown of food using enzymes. Examples: * Amylase * Pepsin ⸻ SALIVA Functions: 1. Moistens food 2. Contains amylase Amylase begins carbohydrate digestion. ⸻ TONGUE Functions: 1. Forms bolus 2. Pushes food for swallowing ⸻ ESOPHAGUS Moves food to stomach. Uses: Peristalsis ⸻ PERISTALSIS Wave-like muscular contractions. Move food through digestive tract. ⸻ STOMACH Functions: * Stores food * Mixes food * Begins protein digestion Produces: * HCl * Pepsin * Mucus ⸻ HCl Hydrochloric Acid Functions: * Kills bacteria * Activates pepsin ⸻ PEPSIN Function: * Digests proteins ⸻ MUCUS Function: * Protects stomach lining ⸻ CHYME Semi-liquid food mixture leaving stomach. ⸻ HEARTBURN Cause: Stomach acid enters esophagus. Usually caused by weakened cardiac sphincter. ⸻ SMALL INTESTINE Main site of: * Digestion * Absorption Adaptations: * Long length * Folds * Villi * Microvilli Large surface area increases absorption. ⸻ DUODENUM First section. Functions: * Receives bile * Receives pancreatic enzymes * Most chemical digestion ⸻ JEJUNUM Main nutrient absorption. ⸻ ILEUM Final nutrient absorption. ⸻ VILLI Finger-like projections. Function: Increase surface area. ⸻ LIVER Functions: * Produces bile * Processes nutrients * Detoxifies blood ⸻ GALL BLADDER Functions: * Stores bile * Releases bile into small intestine ⸻ PANCREAS Functions: * Produces digestive enzymes * Produces bicarbonate ⸻ BILE Function: Emulsifies fats. Breaks large fat droplets into smaller droplets. Makes fat digestion easier. ⸻ DIGESTION OF CARBOHYDRATES Mouth: * Amylase begins digestion Small Intestine: * Pancreatic amylase continues digestion End Product: Glucose ⸻ DIGESTION OF PROTEINS Stomach: * Pepsin begins digestion Small Intestine: * Trypsin continues digestion End Product: Amino Acids ⸻ DIGESTION OF LIPIDS Small Intestine: * Bile emulsifies fats * Lipase digests fats End Product: Fatty Acids + Glycerol ⸻ EVOLUTION Evolution: Change in populations over time. Individuals do NOT evolve. Populations evolve. ⸻ DARWIN Proposed: Natural Selection Book: On the Origin of Species ⸻ WALLACE Independently developed theory of natural selection. ⸻ LAMARCK Proposed: Inheritance of acquired characteristics Example: Giraffes stretch necks and pass longer necks to offspring. This theory is incorrect. ⸻ NATURAL SELECTION Requirements: 1. Variation 2. Overproduction 3. Competition 4. Differential Survival 5. Reproduction Result: Adaptation ⸻ ADAPTATION Inherited characteristic that increases survival and reproduction. ⸻ SELECTIVE ADVANTAGE A characteristic that improves survival or reproduction. Example: Antibiotic resistance ⸻ SELECTIVE PRESSURE Environmental factor that influences survival. Examples: * Predators * Disease * Climate * Competition ⸻ VARIATION Differences among individuals in a population. Sources: * Mutation * Crossing Over * Random Assortment ⸻ MUTATION Ultimate source of new alleles. Creates genetic variation. ⸻ FOSSIL Preserved remains or traces of organisms. ⸻ FOSSIL RECORD Collection of fossils showing evolutionary history. Provides evidence for evolution. ⸻ RADIOACTIVE DATING Uses radioactive isotopes to determine fossil age. ⸻ UNIFORMITARIANISM Proposed by Lyell. Earth changes gradually over long periods of time. ⸻ CATASTROPHISM Proposed by Cuvier. Earth shaped by sudden catastrophic events. ⸻ BIOGEOGRAPHY Study of species distribution around Earth. Provides evidence for evolution. ⸻ EMBRYOLOGY Study of embryos. Similar embryos suggest common ancestry. ⸻ HOMOLOGOUS STRUCTURES Same evolutionary origin. Different functions. Example: Human arm Whale flipper Bat wing Evidence of common ancestry. ⸻ ANALOGOUS STRUCTURES Different origins. Same function. Example: Bird wing Insect wing Not evidence of close ancestry. ⸻ VESTIGIAL STRUCTURES Structures with little or no function. Examples: * Human appendix * Whale pelvis Evidence of evolution. ⸻ MIMICRY One species resembles another. Example: Syrphid fly resembles wasp. Provides protection. ⸻ ARTIFICIAL SELECTION Humans select traits. Examples: * Dog breeding * Crop breeding ⸻ DIRECTIONAL SELECTION One extreme phenotype favored. Graph shifts in one direction. ⸻ STABILIZING SELECTION Average phenotype favored. Extremes selected against. ⸻ DISRUPTIVE SELECTION Both extremes favored. Middle selected against. ⸻ GENETIC DRIFT Random change in allele frequencies. Most significant in small populations. ⸻ FOUNDER EFFECT Small group starts new population. Different allele frequencies from original population. ⸻ BOTTLENECK EFFECT Population drastically reduced. Loss of genetic variation. ⸻ GENE FLOW Movement of alleles between populations. Occurs through migration. ⸻ NON-RANDOM MATING Individuals choose specific mates. Can reduce variation. ⸻ SPECIES A group of organisms that can interbreed in nature and produce fertile offspring. ⸻ SPECIATION Formation of new species. ⸻ ALLOPATRIC SPECIATION Requires: Geographic isolation Example: Mountain separates populations. ⸻ SYMPATRIC SPECIATION Occurs without geographic isolation. ⸻ PRE-ZYGOTIC ISOLATION Prevents fertilization. Examples: * Different mating seasons * Different mating songs * Different habitats ⸻ POST-ZYGOTIC ISOLATION Occurs after fertilization. Example: Sterile hybrids Example: Mule DIVERSITY Prokaryotes vs Eukaryotes PROKARYOTES * No nucleus * No membrane-bound organelles * Circular DNA * Smaller * Examples: Eubacteria, Archaebacteria EUKARYOTES * Nucleus present * Membrane-bound organelles * Linear chromosomes * Larger * Examples: Protists, Fungi, Plants, Animals Three Differences: 1. Nucleus vs no nucleus 2. Organelles vs no organelles 3. Larger vs smaller ⸻ Taxonomy Kingdom Phylum Class Order Family Genus Species Mnemonic: King Philip Came Over For Good Soup ⸻ Binomial Nomenclature Genus + Species Example: Homo sapiens Rules: * Genus capitalized * Species lowercase * Italicized Purpose: * Universal naming system * Avoids confusion * Shows relationships ⸻ Dichotomous Key Used to identify organisms using paired choices. Example: 1a Has wings → Step 2 1b No wings → Step 3 ⸻ Six Kingdoms 1. Archaebacteria 2. Eubacteria 3. Protista 4. Fungi 5. Plantae 6. Animalia ⸻ VIRUSES Virus Structure: * DNA or RNA * Capsid * Attachment proteins * Sometimes envelope Why Viruses Are Not Living: * Not made of cells * Cannot reproduce independently * No metabolism * Need host cell ⸻ DNA Virus vs RNA Virus DNA Virus: * Contains DNA * More stable RNA Virus: * Contains RNA * Mutates faster ⸻ Lytic Cycle Attachment ↓ Penetration ↓ Replication ↓ Assembly ↓ Lysis Host cell bursts. ⸻ Lysogenic Cycle Attachment ↓ Penetration ↓ Integration into host DNA ↓ Host reproduces ↓ Virus DNA copied Cell survives initially. ⸻ ARCHAEBACTERIA Characteristics: * Prokaryotic * Unicellular * Extreme environments Three Groups: Methanogens * Produce methane Halophiles * Salt-loving Thermoacidophiles * Hot acidic environments ⸻ EUBACTERIA Characteristics: * Prokaryotic * Peptidoglycan cell wall * Binary fission Examples: * E. coli * Streptococcus ⸻ Binary Fission DNA Replication ↓ Cell Growth ↓ Cell Division ↓ Two Identical Cells ⸻ Conjugation DNA transfer through pilus. Importance: * Genetic variation * Antibiotic resistance ⸻ Antibiotic Resistance Mutation ↓ Antibiotic kills susceptible bacteria ↓ Resistant bacteria survive ↓ Resistant bacteria reproduce Natural Selection ⸻ PROTISTS Characteristics: * Eukaryotic * Mostly unicellular * Aquatic Three Groups: Animal-like * Amoeba * Paramecium Plant-like * Algae * Euglena Fungus-like * Slime molds ⸻ Amoeba * Uses pseudopods * Phagocytosis ⸻ Algae * Photosynthetic * Oxygen producer ⸻ Euglena * Chloroplasts * Flagellum * Photosynthesis * Can also feed heterotrophically ⸻ Malaria Cause: Plasmodium Kingdom: Protista ⸻ FUNGI Characteristics: * Eukaryotic * Heterotrophic * Chitin cell walls * Reproduce with spores Examples: * Mushrooms * Mold * Yeast ⸻ External Digestion Release enzymes ↓ Digest food outside body ↓ Absorb nutrients ⸻ Fungi vs Plants FUNGI * Heterotrophic * Chitin * No chloroplasts PLANTS * Autotrophic * Cellulose * Chloroplasts ⸻ PLANTS Biodiversity vs Monoculture BIODIVERSITY * Many species * Stable ecosystem * Disease resistance MONOCULTURE * One crop species * Low diversity * Disease risk ⸻ Bryophytes Definition: Nonvascular plants Examples: * Mosses * Liverworts Characteristics: * No xylem * No phloem * Need water for reproduction ⸻ Vascular Plants Contain: * Xylem * Phloem ⸻ Xylem Function: Water and minerals Direction: Roots → Leaves ⸻ Phloem Function: Sugars Direction: Throughout plant ⸻ Alternation of Generations Sporophyte (2n) ↓ meiosis Spores (n) ↓ Gametophyte (n) ↓ Gametes ↓ fertilization Zygote (2n) ↓ Sporophyte ⸻ Moss Life Cycle Spores ↓ Gametophyte ↓ Egg + Sperm ↓ Zygote ↓ Sporophyte ↓ Capsule ↓ Spores Know: * Capsule * Sporophyte * Gametophyte * Spores ⸻ Fern Life Cycle Fern ↓ Sori ↓ Spores ↓ Prothallus ↓ Gametes ↓ Fertilization ↓ Young Fern Know: * Frond * Sori * Sporangia * Prothallus ⸻ Gymnosperms Characteristics: * Naked seeds * Cones * Wind pollination * Evergreen Examples: * Pine * Spruce * Fir ⸻ Angiosperms Characteristics: * Flowers * Fruit * Seeds enclosed Examples: * Apple tree * Rose * Maple ⸻ Flower Structure Anther * Produces pollen Pollen Grain * Male gamete Stigma * Receives pollen Style * Connects stigma and ovary Ovary * Contains ovules Ovule * Female gamete Petals * Attract pollinators ⸻ Plant Tissues Meristematic * Growth Dermal * Protection Ground * Photosynthesis * Storage Vascular * Transport ⸻ Leaf Structure Blade * Main leaf surface Petiole * Connects leaf to stem Cuticle * Reduces water loss Palisade Mesophyll * Photosynthesis Spongy Mesophyll * Gas exchange Veins * Xylem + Phloem ⸻ Stomata Openings in leaves. Functions: * Gas exchange * Water loss ⸻ Guard Cells Control opening and closing of stomata. ⸻ Transpiration Water loss from leaves. Functions: * Pulls water upward * Cools plant * Moves minerals ⸻ Simple vs Compound Leaves Simple: * One blade Compound: * Multiple leaflets ⸻ Monocots vs Dicots MONOCOTS * 1 cotyledon * Parallel veins * Fibrous roots * Flower parts in 3s Examples: Corn Grass DICOTS * 2 cotyledons * Net veins * Taproot * Flower parts in 4s or 5s Examples: Bean Maple ⸻ Seeds Contain: * Embryo * Stored food * Seed coat Functions: * Protection * Survival * Dispersal ⸻ Seed Dispersal Wind * Dandelion Water * Coconut Animals * Burrs Explosive * Touch-me-not ⸻ Fruit vs Vegetable Fruit: * Comes from ovary * Contains seeds Examples: Tomato Apple Pepper Vegetable: * Root, stem, leaf, or flower Examples: Carrot Celery Broccoli ⸻ Factors Affecting Plant Growth 1. Light 2. Water 3. Carbon dioxide 4. Temperature 5. Soil nutrients 6. Oxygen 7. Soil pH 8. Space 9. Pollinators 10. Disease and pests