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

Digestive System Terminology (digestive system - trypsin)

🌱🧪 Biochemia - 🌱⚙️ Enzymy (📱)

🌱🧪 Biochemia - 🌱⚙️ Enzymy

🌱🧪 Biochemia - 🌱⚙️ Enzymy (reduced)

🌱🧪 Biochemia - 🌱⚙️ Enzymy (repetitions)

🌱🧪 Biochemia - 🌱⚙️ Enzymy - 🧩♨️ Koenzymy Transferaz i Trawienie

🌱🧪 Biochemia - 🌱⚙️ Enzymy - 🔀🌀 Klasy 3–6 – Hydrolazy, Liazy, Izomerazy, Ligazy

Practical 7 - Enzyme concentration on trypsin

Digestion Notes (Biology 12) I. Introduction/Overview • Digestion: Breakdown of food into small, soluble molecules • Occurs physically and chemically • Absorption: The process of taking specific compounds into the body • Elimination: Expulsion of materials not absorbed into the body • Excretion: Removal of waste from metabolic processes II. Location of Parts and Function A. Teeth • Type of teeth depends on diet: • Carnivores: Sharp teeth for grasping prey and severing meat • Herbivores: Flat teeth for crushing plant fibers • Omnivores: A combination of tooth types for eating both meat and plants • Structure: • Enamel: Hard outer layer • Dentin: Bony layer under enamel • Pulp: Living part of the tooth (contains nerves and blood vessels) • Teeth are embedded in sockets in the jaw B. Tongue • Functions: • Taste: Detects salt, sour, sweet, and bitter flavors • Positioning food for chewing C. Salivary Glands • Three pairs: • Parotid (side of face; swells with mumps) • Sublingual (under tongue) • Submandibular (lower jaw) • Produce saliva, which contains enzymes for digestion D. Palates • Located at the top of the mouth • Hard palate: Front, separates the mouth from the nasal cavity • Soft palate: Back, ends in the uvula E. Pharynx • Area between mouth and esophagus • Used for both breathing and eating • Epiglottis: Closes over the glottis when swallowing to prevent choking F. Esophagus • Muscular tube that pushes food into the stomach using peristalsis • Composed of five tissue layers: 1. Mucosa (epithelial lining) 2. Submucosa (connective tissue) 3. Muscularis (two muscle layers: circular and longitudinal) 4. Serosa (outer epithelial layer; secretes fluid for lubrication) G. Cardiac Sphincter • Muscle at the junction of the esophagus and stomach • Opens to allow food into the stomach H. Stomach • J-shaped organ, located left of the body’s center • Capacity: About 1 liter • Inner lining contains gastric glands: • Parietal cells → Produce HCl • Chief cells → Produce pepsinogen, activated by HCl into pepsin • Epithelial cells → Produce mucus (protects stomach lining) • Functions: • Storage of food (empties in 2-6 hours) • Digestion using pepsin and salivary amylase • Absorption of water, ethanol • Regulation of pepsin production by the hormone gastrin I. Pyloric Sphincter • Muscle at the junction of the stomach and small intestine • Opens to allow chyme (partially digested food) into the small intestine J. Small Intestine • Length: ~ 3 meters (10 feet) • Highly convoluted to increase surface area for absorption • Interior folds covered with villi (tiny projections that increase surface area) • Divided into three parts: 1. Duodenum (first 25 cm): Produces lactase, peptidase, maltase, nuclease 2. Jejunum 3. Ileum • Functions: • Completes digestion • Absorbs nutrients into the bloodstream K. Liver • Largest organ in the body • Monitors blood composition via the hepatic portal vein L. Pancreas • Produces pancreatic juice (digestive enzymes and sodium bicarbonate to neutralize stomach acid) • Produces insulin (regulates blood glucose) M. Ileo-Caecal Opening • Joins the small intestine to the large intestine N. Caecum • Blind pouch at the end of the small intestine • No function in humans (vestigial), but in herbivores, it helps digest cellulose O. Large Intestine • Parts: 1. Ascending colon 2. Transverse colon 3. Descending colon 4. Rectum (stores feces) 5. Anus (controls feces release) • Functions: • Reabsorbs water (~95% of 10L daily intake) • Forms feces • Produces vitamins B and K using E. coli bacteria III. Digestive Enzymes Enzyme Source pH Digested Food Product Salivary Amylase Salivary Glands 7 Starch Maltose Pepsin Stomach 2 Protein Peptides Pancreatic Amylase Pancreas Basic Starch Maltose Trypsin Pancreas Basic Protein Peptides Lipase Pancreas Basic Fat Glycerol & Fatty Acids Peptidases Small Intestine Basic Peptides Amino Acids Maltase Small Intestine Basic Maltose Glucose Nuclease Pancreas Basic DNA/RNA Nucleotides IV. Swallowing and Peristalsis • Swallowing: Food forms a bolus (food ball) and is moved down the esophagus • Peristalsis: Rhythmic contractions of smooth muscle that push food through the digestive tract V. The 7 Functions of the Liver 1. Detoxifies harmful substances (e.g., alcohol) 2. Stores glucose as glycogen 3. Destroys old red blood cells (recycling heme into bile) 4. Produces urea from amino acid breakdown 5. Makes blood proteins 6. Stores iron and vitamins A, D, E, K 7. Converts amino acids to glucose if needed (gluconeogenesis) VI. Digestive Juices & Hormones Gastric Juice (Stomach) • Contains HCl, pepsinogen (activated into pepsin), and mucus • Helps digest proteins into peptides Pancreatic Juice • Contains sodium bicarbonate (neutralizes acid) • Enzymes: Pancreatic amylase, trypsin, lipase, nuclease Bile (Liver & Gallbladder) • Breaks down fats into small droplets for lipase to act on VII. Control of Digestive Gland Secretions • Nervous Reflex: Presence of food triggers digestion • Conditioned Reflex: External stimuli (e.g

Chapter 9 – Skeletal Muscles 1. Connective Tissue Surrounding a Skeletal Muscle: • Epimysium: Surrounds the entire muscle. • Perimysium: Surrounds bundles of muscle fibers (fascicles). • Endomysium: Surrounds individual muscle fibers. 2. Histology and Function of Sarcomeres: • Histology: Sarcomeres are the structural and functional units of skeletal muscles, composed of repeating units between two Z-lines. • Function: They enable muscle contraction through the sliding filament mechanism. 3. Main Components: • Thin Filaments: Actin, tropomyosin, and troponin. • Thick Filaments: Myosin. 4. Function of Transverse Tubules and Sarcoplasmic Reticulum: • Transverse Tubules (T-tubules): Transmit action potentials deep into the muscle fiber. • Sarcoplasmic Reticulum: Stores and releases calcium ions for muscle contraction. 5. Motor Unit: A motor neuron and all the muscle fibers it innervates. 6. Neuromuscular Junction: The synapse where a motor neuron meets a muscle fiber, allowing for signal transmission. 7. Synapse: A junction between two neurons or a neuron and a muscle cell where communication occurs. 8. Actions of Acetylcholine (ACh): • Initiates muscle contraction by binding to receptors on the sarcolemma. • Degraded by: Acetylcholinesterase. 9. Neurotransmitter Released at Motor Axon Terminals: Acetylcholine. 10. Steps in Excitation-Contraction Coupling: • Action potential travels along sarcolemma. • Calcium is released from the sarcoplasmic reticulum. • Calcium binds to troponin, causing tropomyosin to move, exposing binding sites on actin. • Myosin heads form cross-bridges and initiate contraction. 11. Order of Muscle Fiber Contraction: • Action potential → Calcium release → Cross-bridge formation → Power stroke → ATP binding → Cross-bridge detachment. 12. Mechanism of Muscle Contraction: • Sliding filament theory: Actin and myosin filaments slide past each other. 13. Interaction of Actin, Myosin, and Calcium: • Calcium binds to troponin, shifting tropomyosin to expose myosin-binding sites on actin, enabling cross-bridge cycling. 14. Cross-Bridges: Myosin heads that bind to actin during contraction. 15. Contraction Types: • Isotonic: Muscle length changes. • Eccentric: Muscle lengthens under tension. • Isometric: Muscle tension without length change. • Concentric: Muscle shortens under tension. 16. Force of Muscle Contraction: • Controlled by motor unit recruitment. • Partial Tetany: Incomplete relaxation. • Fused Tetany: Sustained contraction without relaxation. 17. Bones and Muscles as Levers: • Fulcrum: Pivot point of the lever. 18. Synergist and Antagonist: • Synergist: Assists the primary mover. • Antagonist: Opposes the primary mover. 19. Muscle Atrophy: Wasting of muscle due to disuse or disease. 20. Myasthenia Gravis: Autoimmune disorder causing muscle weakness by targeting ACh receptors. 21. Linea Alba: A fibrous structure running down the midline of the abdomen. 22. Origin, Insertion, and Actions of Specific Muscles: (Let me know which specific ones you’d like to focus on.) Chapter 17 – Digestive System 1. Alimentary Canal: A continuous muscular tube extending from the mouth to the anus. 2. Functions of the Digestive System: • Ingestion, digestion, absorption, and elimination. 3. Breakdown and Absorption: • Carbohydrates: Begin in the mouth (amylase). • Proteins: Start in the stomach (pepsin). • Fats: Start in the small intestine (lipase, bile). 4. Layers of Alimentary Canal Walls: • Mucosa, submucosa, muscularis, serosa. 5. Accessory Organs: • Liver, pancreas, gallbladder. 6. Sympathetic vs. Parasympathetic Effects: • Sympathetic: Decreases digestion. • Parasympathetic: Enhances digestion. 7. Hormones: • Gastrin: Stimulates gastric juice secretion. • Cholecystokinin (CCK): Stimulates bile and pancreatic juice. • Secretin: Stimulates bicarbonate secretion. 8. Peristalsis vs. Segmentation: • Peristalsis: Wave-like contractions. • Segmentation: Mixing movements. 9. Epiglottis Function: Prevents food from entering the trachea. 10. Heartburn: Caused by stomach acid reflux into the esophagus. 11. Stomach Parts: Fundus, body, pylorus. 12. Secretions: • Parietal Cells: Hydrochloric acid, intrinsic factor. • Chief Cells: Pepsinogen. 13. Digestive Enzymes and Substances: • Amylase: Breaks down starch. • Pepsin: Digests proteins. • Trypsin: Protein digestion. • Lipase: Fat digestion. • Bile Salts: Emulsify fats. 14. Liver, Gallbladder, Pancreas Functions: • Liver: Produces bile. • Gallbladder: Stores bile. • Pancreas: Produces enzymes and bicarbonate. 15. Anatomy of Bile Ducts: • Common hepatic, cystic, and pancreatic ducts form the common bile duct. 16. Functions of Large Intestine: • Absorption of water, vitamin production, and feces formation. 17. Defecation Reflex: Triggered by rectal wall distension. Chapter 18 – Nutrition 1. Excess Glucose Storage: As glycogen in the liver and muscles. 2. Tissue Requiring Glucose: Nervous tissue (brain). 3. Triglyceride Components: Glycerol and three fatty acids. 4. Essential Amino Acids: Cannot be synthesized by the body

Practical 8: Trypsin activity in earthworms