Biology Grade 11 Comprehensive Study Notes

TEXTBOOK AND IDENTIFICATION DATA\n\n* Subject: Biology\n* Grade: $11$\n* Year: $2023$\n* Publication Authority: Federal Democratic Republic of Ethiopia, Ministry of Education (FDRE-MoE).\n* Textbook Property: Property of the school. Rules for care include:\n * $1.$ Cover the book with protective materials (plastic, newspapers, magazines).\n * $2.$ Keep in a clear, dry place.\n * $3.$ Use with clean hands.\n * $4.$ Do not write on covers or inside pages.\n * $5.$ Use paper/cardboard as markers.\n * $6.$ Never tear or cut out pictures.\n * $7.$ Repair torn pages with paste/tape.\n * $8.$ Pack carefully in school bags.\n * $9.$ Handle with care when passing to others.\n * $10.$ For new books, lay on back, open a few pages at a time, and press lightly along the bound edge.\n* Authors: Habtamu Wodaj (PhD), Sutuma Edessa (PhD).\n* Editors: Meskerem Cheru (MSc) [Pedagogical], Destaw Damtie (PhD) [Content], Yenus Nurie (PhD) [Language].\n* Design/Illustration: Nega Tassie (PhD) [Illustrator], Ali Seid (PhD) [Designer].\n* Copyright: Proclamation No. $410/2004$, \"Copyright and Neighboring Rights Protection.\"\n* ISBN: $978-99990-0-010-9$\n\n# TABLE OF CONTENTS\n\n* Unit One: Biology and Technology\n * $1.1$ Learning from nature\n * $1.2$ Biology and technology\n * $1.3$ Impacts of biology and technology on society and the natural world\n * $1.4$ Ethical issues in biology\n* Unit Two: Animals\n * $2.1$ Characteristics of animals\n * $2.2$ Invertebrates and Vertebrates\n * $2.3$ Reproduction in Animals\n * $2.4$ The economic importance of animals (insects)\n * $2.5$ Animal Behavior\n * $2.6$ Homeostasis in animals\n * $2.7$ Renowned zoologists in Ethiopia\n* Unit Three: Enzymes\n * $3.1$ What are enzymes?\n * $3.2$ Properties and functions of enzymes\n * $3.3$ Protein structures\n * $3.4$ Enzyme substrate models\n * $3.5$ Enzyme regulation\n * $3.6$ Types of enzymes\n * $3.7$ Factors affecting enzyme action\n * $3.8$ Enzyme kinetics\n * $3.9$ Application of enzymes in industries and their benefits\n * $3.10$ Malting in Ethiopian tradition\n * $3.11$ Renowned Biochemists in Ethiopia\n* Unit Four: Genetics\n * $4.1$ The genetic materials\n * $4.2$ The structure and function of DNA and RNA\n * $4.3$ The process of cell division\n * $4.4$ Protein synthesis\n * $4.5$ Mendelian inheritance\n * $4.6$ Sex determination\n * $4.7$ Non-Mendelian inheritance\n * $4.8$ Human pedigree analysis and its importance\n * $4.9$ Genetic disorders\n * $4.10$ Genetic testing and counseling\n * $4.11$ Gene therapy\n * $4.12$ Breeding\n * $4.13$ Bioinformatics introduction\n* Unit Five: The human body systems\n * $5.1$ Human Musculoskeletal Systems\n * $5.2$ The reproductive system\n * $5.3$ Harmful traditional practices\n * $5.4$ Family planning\n * $5.5$ Effects of drug use on STIs and pregnancy\n* Unit Six: Population and natural resources\n * $6.1$ Population Ecology\n * $6.2$ Natural resources\n * $6.3$ Conservation of natural resources in Ethiopia\n * $6.4$ Impact of traffic accidents on animals\n * $6.5$ Impact of human activities on the environment\n * $6.6$ Indigenous conservation practices in Ethiopia\n\n# UNIT ONE: BIOLOGY AND TECHNOLOGY\n\n## LEARNING FROM NATURE (BIOMIMICRY)\n\n* Definition: Nature is the physical, material world existing without human intervention, including ecosystems, weather, organisms, and geology.\n* Mechanism: Scientists and engineers use imitation of physical structures, shapes, and functional mechanisms of natural facts at macro and nano scales.\n* Key Examples of Natural Imitation:\n * $1.$ Swallow nests: Inspired house building design.\n * $2.$ Spider webs: Developed weaving technologies.\n * $3.$ Termite mounds: Inspired the East Gate Center in Harare, which uses chimneys and architecture to maintain constant temperature and humidity.\n * $4.$ Bird/Bat wings: Principles of heavy aircraft flight and wing design.\n * $5.$ Human eyes: Camera lens technology.\n * $6.$ Kangaroo movement: Bio-robot movement design.\n * $7.$ Mosquito proboscis: Design of injection needles.\n * $8.$ Neurons: Sensors of electrical devices.\n * $9.$ Sharp teeth: The cutting saw.\n * $10.$ Spider silkin: Synthetic bulletproof vests.\n * $11.$ Shellfish exoskeleton: Crack-resistant ceramics.\n * $12.$ Elephant trunk: Robotic arm design.\n * $13.$ Kingfisher beak: Streamlined noses of Japanese bullet trains to dive into air/tunnel without noise shock.\n\n## BIOLOGY AND TECHNOLOGY RELATIONSHIP\n\n* Definitions:\n * Biology: The study of life structures, functions, growth, and evolution.\n * Technology: Application of scientific knowledge/skills for producing devices and investigating questions.\n * Biotechnology: The blend of biology and technology, utilizing biological systems to develop products (e.g., yeast for bread/beer).\n* Benefits of Biology to Technology: Sources of materials and design (medicinal plant substances, Gene engineering to cure genetic conditions, biosynthetic materials for tissue repair).\n* Uses of Technology in Biology (Advanced Studies):\n * Biochemical studies: Investigate carbohydrates, proteins, lipids, and nucleic acids.\n * Biomedical studies: Investigate chemical components of medicinal plants.\n * Biophysical studies: Gather biological data at molecular, organismic, and population scales.\n * Bioinformatics: Uses computer tech to analyze DNA and amino acid sequences.\n * Biogeographical studies: GPS usage for mapping species distribution.\n* Key Technological Devices:\n * Digital Thermometer: Measures body temperatures.\n * Pregnancy Urine Test: Detects Human Chorionic Gonadotropin (HCG) six to ten days after fertilization.\n * Diabetic Blood Test: Measures blood sugar from finger tips.\n * HIV Test: Detects infection status.\n * Microscopy: Object magnification.\n * CT Scan (Computed Tomography): Sophisticated X-ray tech for disease screening.\n * PET Scan (Positron Emission Tomography): Uses radioactive tracers to visualize metabolic changes and blood flow.\n\n## IMPACTS ON SOCIETY AND THE NATURAL WORLD\n\n* Positive Impacts of Biology: Food security (increased productivity), improved health/longevity via medicine, energy/clean water supply, industrial production via microbial action, and antibiotics.\n* Negative/Dual Impacts of Biology: Biological weapon production; child sex selection affecting chromosome balance in society.\n* Impact of Technology: Solving societal problems vs. pollution and resource depletion.\n * Industrial Emissions: Pollutes air and water.\n * Biochemical Agents: Pesticides and fertilizers causing toxicity/biohazards.\n\n## ETHICAL ISSUES IN BIOLOGY\n\n* Definition: Concerns regarding the rightness/wrongness of using biological discoveries, biotech products, or devices on human health and the environment.\n* Ethical Treatment of Plants:\n * Plants are decentralized (no brain) but vital primary producers.\n * Unethical acts: Destructive seed testing, excessive cutting for experiment, deforestation, unplanned burning, restructure for aesthetics.\n* Ethical Treatment of Animals:\n * Animals are sentient creatures (feel pain and stress).\n * The Three Rs Principle:\n * Reduction: Minimizing animal numbers via improved techniques.\n * Refinement: Using less invasive techniques and better care to reduce suffering.\n * Replacement: Substituting with cell cultures, biosynthesis, or computer models.\n\n# UNIT TWO: ANIMALS\n\n## CHARACTERISTICS OF ANIMALS\n\n* Common Traits: Eukaryotic, multicellular, heterotrophic, sensitive to stimuli, reproduction, motility, respiration, excretion, growth, and body symmetry.\n* Classification:\n * Invertebrates: No backbone. Most diverse ($95 \\%$ of animal species). Examples: Porifera, Platyhelminthes, Cnidaria, Arthropoda (Crustacea, Spiders, Insects, Many-legs), Annelida, Mollusca.\n * Vertebrates: Advanced internal skeleton with backbone. Divided into:\n * Homeothermic (Warm-blooded): Mammals and Birds.\n * Poikilothermic (Cold-blooded): Fish, Reptiles, Amphibians.\n\n## ANIMAL REPRODUCTION\n\n* Asexual Reproduction: Single parent, no gamete fusion. Types: Budding, Fragmentation, and Parthenogenesis (unfertilized eggs develop into offspring, e.g., in some insects/vertebrates).\n* Sexual Reproduction: Involves gamete fusion (Sperm $[n]$ + Ovum $[n]$ = Zygote $[2n]$).\n * Embryonic Development Stages:\n * $1.$ Cleavage: Mitotic divisions resulting in an 8-celled structure.\n * $2.$ Blastula formation: Hollow ball of cells.\n * $3.$ Gastrulation: Formation of the gastrula with germ layers.\n * $4.$ Organogenesis: Development of germ layers into tissues and organs.\n\n### TAXON-SPECIFIC REPRODUCTION\n\n* Insects (Metamorphosis):\n * Complete: 4 stages (Egg \rightarrow Larva \rightarrow Pupa \rightarrow Adult, e.g., Honeybee).\n * Incomplete: 3 stages (Egg \rightarrow Nymph \rightarrow Adult, e.g., Grasshopper).\n* Frogs: External fertilization. Eggs covered in a jelly-like substance in water. Development: Egg \rightarrow Tadpole (larva) \rightarrow Adult frog.\n* Crocodiles: Internal fertilization (mating in water). Hard leathery eggs buried in sand ($10$ to $100$ eggs). No larval stage.\n* Birds: Internal fertilization (via cloaca). Most are monogamous.\n * Oviduct Parts: Infundibulum (yolk engulfing), Magnum (albumen secretion), Isthmus (shell membranes), Uterus (shell formation), Vagina.\n * Egg structure: Yolk, Chalaza, Albumen, Membranes, Air sac, Shell.\n * Incubation: Staying warm via a \"brood patch\" (skin with high blood vessels).\n * Hatching: Use of an \"egg tooth\" (hard tip of bill) to break out.\n* Rats (Mammalian Mode): \n * Gestation: Black rat ($22$ days), Brown rat ($22-24$ days), Giant Mole rat ($37-49$ days).\n * Structure: Umbilical cord, Placenta (nutrient/waste), Amniotic sac (protection).\n * Care: Pups/kittens born hairless and deaf. Weaning after $45$ days.\n\n## ECONOMIC IMPORTANCE OF INSECTS\n\n* Beneficial Aspects:\n * Agriculture: Pollinators ($35 \\%$ of world crops). Biological pest control (Mantis, Lady birds, Blister beetles).\n * Food: Source of protein; over $1,462$ edible species globally.\n * Industry: Honey/Wax (Honeybees), Silk (Silkworms - $Bombyx \\, mori$), Shellac (Lac insects - $Laccifer \\, lacca$), Cochineal (Dyes from $Dacylopius \\, coccus$), Tannic Acid (Wasps).\n * Medicine: Honey for burns; Bee/Ant venom for joint pain; Cantharidan (Blister beetle) for viral/cancer research.\n* Harmful Aspects: Crop pests (Locusts, Aphids); Stored grain pests (Rice Weevil); Vectors (Mosquitoes: Malaria, Filariasis; Tsetse fly: Sleeping Sickness).\n\n## ANIMAL BEHAVIOR\n\n* Innate Behavior: Genetically determined.\n * Instinct: Web making, nest building.\n * Reflex: Blinking, pulling hand from heat.\n * Orientation: Taxis (directed movement toward/away from stimulus) and Kinesis (undirected random movement).\n* Learned Behavior: Conditioned by experience.\n * Habituation: Stop responding to a repetitive harmless stimulus.\n * Classical Conditioning: Pavlov’s dog (CS + UCS = CR).\n * Operant Conditioning: B.F. Skinner (Reward and punishment; Neutral operants, Reinforcers, Punishers).\n * Insight Learning: Reasoning based on past experience (Hallmark of human behavior).\n * Sensitization: Progressive amplification of a response (reverse tolerance).\n* Patterns of Behavior: Circadian rhythms ($24$-hour clock), Seasonal migration, Social behavior (Division of labor in ants/bees), Competition (Intraspecific and Interspecific), Territoriality (Marking with pheromones/urine), and Communication (Sound, Sight, Touch, Pheromones).\n\n## HOMEOSTASIS\n\n* Components: Stimulus \rightarrow Receptor \rightarrow Control Center (Hypothalamus) \rightarrow Effector.\n* Thermoregulation:\n * Poikilotherms: Body temp matches environment (Ectothermic).\n * Homeotherms: Internal control (Endothermic). Methods: Vasoconstriction/Shivering (cold), Vasodilation/Sweating (hot).\n * Surface-Area-to-Volume Ratio: Smaller animals (high ratio) lose heat faster; larger animals (low ratio) retain heat better.\n* Osmoregulation: Control of water/electrolytes. Hypothalamus and Antidiuretic hormone (ADH) control kidney function.\n* Blood Sugar Regulation: Controlled by Pancreas.\n * Insulin: Lowers high glucose levels by converting it to glycogen in the liver.\n * Glucagon: Raises low glucose levels by converting glycogen back to glucose.\n* Feedback Loops:\n * Negative Feedback: Reverses a stimulus (most homeostatic mechanisms).\n * Positive Feedback: Accelerates a process (e.g., childbirth contractions, ovulation).\n\n# UNIT THREE: ENZYMES\n\n## GENERAL NATURE\n\n* Definition: Protein molecules acting as biological catalysts (biocatalysts) that accelerate reaction rates by lowering Activation Energy ($E_a$).\n* Metabolism: Totality of chemical changes including Catabolism (breakdown) and Anabolism (synthesis).\n* Physical Properties: Denaturation (distorting shape by heat/pH), Solubility (water/salts), Colloidal nature (high molecular weight), Biocatalyst efficiency (small amount converts large substrate).\n* Chemical Properties: Sensitivity (pH/Heat), Regulation, Specificity, Reversibility.\n* Specificity Types: Bond, Group, Substrate, Optical, and Co-factor specificity.\n\n## PROTEIN STRUCTURE AND ENZYME MODELS\n\n* Levels of Protein Structure:\n * $1.$ Primary: Linear sequence of amino acids linked by peptide bonds.\n * $2.$ Secondary: $\alpha$-helix (coiled) and $\beta$-pleated sheet (side-by-side) formed by hydrogen bonds.\n * $3.$ Tertiary: Three-dimensional shape achieving maximum stability.\n * $4.$ Quaternary: Association of multiple polypeptide subunits (e.g., Hemoglobin).\n* Enzyme-Substrate Models:\n * Lock and Key: Substrate fits perfectly into the rigid active site.\n * Induced Fit: Active site molds slightly upon substrate binding to stabilize the transition state.\n\n## ENZYME REGULATION AND CLASSIFICATION\n\n* Regulation Mechanisms:\n * Allosteric: Effector molecules bind to a site other than the active site.\n * Covalent Modification: Phosphorylation (adding phosphate) to activate/deactivate.\n* Inhibitors:\n * Reversible: Competitive (blocks active site), Noncompetitive (binds elsewhere to stop efficacy), Uncompetitive (binds ES complex).\n * Irreversible: Permanently blocks action.\n* Structural Classification: Simple proteins vs. Holoenzymes (Apoenzyme [protein] + Cofactor [non-protein]).\n* Basic Classes (Six):\n * $1.$ Oxidoreductases: Electron transfer.\n * $2.$ Transferase: Group transfer (e.g., methyl).\n * $3.$ Hydrolases: Hydrolysis bond cleavage.\n * $4.$ Lyases: Non-hydrolytic bond cleavage.\n * $5.$ Isomerases: Isomeric conversion.\n * $6.$ Ligases: Joining molecules using ATP.\n\n## ENZYME KINETICS AND APPLICATION\n\n* Michaelis-Menten Equation:\n $V_1 = \\frac{V_{max} [S]}{K_M + [S]}$\n * $V_1$: Initial velocity.\n * $V_{max}$: Max rate.\n * $K_M$: Michaelis constant (substrate concentration at half-max velocity).\n* Industrial Applications:\n * Biofuel: Cellulases break down cellulose.\n * Detergents: Proteases (proteins), Amylases (starch), Lipases (fats).\n * Food: Rennin (cheese), Papain (meat tenderizer), Pectinase (juice clarification).\n* Malting: Stepwise traditional/modern tech involving Steeping (soaking), Germinating (triggering $\alpha$- and $\beta$-amylase), and Kilning (heating to dry and stabilize flavor/color).\n\n# UNIT FOUR: GENETICS\n\n## THE GENETIC MATERIAL\n\n* DNA (Deoxyribonucleic acid): Double helix structure discovering by Watson and Crick.\n * Nucleotide: Phosphate + Deoxyribose sugar + Base.\n * Bases: Purines (Adenine, Guanine), Pyrimidines (Cytosine, Thymine). Pairing: $A-T$, $C-G$.\n* RNA (Ribonucleic acid): Single strand. Ribose sugar. Uracil (U) replaces Thymine.\n * Types: mRNA (messenger), tRNA (transfer), rRNA (ribosomal).\n* Chromosomes: DNA + Histone proteins. Located at specific spots called Loci.\n\n## GENE EXPRESSION AND DIVISION\n\n* Central Dogma: DNA \rightarrow (Transcription) \rightarrow RNA \rightarrow (Translation) \rightarrow Protein.\n* Transcription: Synthesis of mRNA in the nucleus via RNA polymerase.\n* Translation: Synthesis of polypeptide at ribosome. Codon (mRNA triplet) pairs with Anticodon (tRNA). Includes Start (AUG) and Stop (UAG, UAA, UGA) codons.\n* Cell Cycle: Interphase ($G_1$, $S$ [DNA replication], $G_2$) and Mitotic Phase.\n* Mitosis: Somatic division (Prophase, Metaphase, Anaphase, Telophase). Result: Two identical $2n$ cells.\n* Meiosis: Gamete division (Meiosis I [reduction] and Meiosis II). Result: Four non-identical $n$ cells. Crossing over occurs in Prophase I for variation.\n\n## INHERITANCE PATTERNS\n\n* Mendelian Laws:\n * Law of Segregation: Alleles separate during gamete formation.\n * Law of Independent Assortment: Different traits relate independently during game formation (found in dihybrid crosses).\n * Dihybrid Ratio: $9:3:3:1$. Monohybrid Ratio: $3:1$ (Phenotypic), $1:2:1$ (Genotypic).\n * Test Cross: Crossing dominant phenotype with homozygous recessive parent to find unknown genotype.\n* Non-Mendelian:\n * Co-dominance: Both expressed equally (AB blood group, Roan cattle).\n * Incomplete dominance: Intermediate phenotype (Pink roses).\n * Multiple Alleles: ABO Blood groups ($I^A$, $I^B$, $i$).\n* Rhesus (Rh) Factor: Rh+ is dominant. Risk of Rh sensitization if Rh- mother has Rh+ fetus (treated with anti-D vaccine).\n* Sex Determination: Humans (XX = female, XY = male). Sex-linked traits like Hemophilia/Color blindness often affect males more.\n\n## DISORDERS AND BIOTECH\n\n* Genetic Disorders: Single-gene (Huntington's [dominant], Cystic fibrosis [recessive]), Chromosomal (Down Syndrome [Trisomy $21$], Aneuploidy), and Multifactorial (Diabetes, Cancer).\n* Gene Therapy: Somatic (non-heritable) and Germ-line (heritable) modification. Vectors: Plasmids, Viral, Bacterial.\n* Breeding: Selective breeding (Inbreeding for pure lines; Crossbreeding for hybrid vigor). Indigenous Ethiopian knowledge is rich in crop diversity (Coffee, Tef, Enset).\n* Bioinformatics: Merging biology and CS. Fields: Genomics, Proteomics, Systems Biology.\n\n# UNIT FIVE: THE HUMAN BODY SYSTEMS\n\n## MUSCULOSKELETAL SYSTEM\n\n* Skeleton: $206$ bones in adults ($300+$ at birth). Cells: Osteoblasts (build), Osteocytes (maintain), Osteoclasts (break down).\n * Axial ($80$ bones): Skull ($22$), Ossicles ($6$), Hyoid ($1$), Ribs ($24$), Sternum ($1$), Vertebral Column ($26$).\n * Appendicular ($126$ bones): Girdles and Limbs.\n * Joints: Ball and socket (shoulder), Hinge (knee), Condyloid (jaw), Pivot (neck), Gliding (wrist), Saddle (thumb).\n* Muscles: $700$ muscles ($30-40 \\%$ body mass).\n * Types: Cardiac (striated, involuntary), Skeletal (striated, voluntary), Smooth (non-striated, involuntary).\n * Sliding Filament Theory: Actin (thin) and Myosin (thick) filaments slide to generate tension using Calcium and ATP.\n * Contraction Types: Isometric (length constant), Concentric (shorten), Eccentric (lengthen).\n\n## REPRODUCTIVE SYSTEM\n\n* Male: Testes (sperm/testosterone production), Seminiferous tubules, Epididymis (storage), Vas deferens, Penis, Prostate/Seminal vesicles (alkaline buffer/energy).\n* Female: Ovaries (eggs/estrogen), Fallopian tubes (site of fertilization), Uterus (womb), Cervix, Vagina.\n* Fertilization: Union in the ampulla of fallopian tube. Gestation usually $40$ weeks.\n* Menstrual Cycle (28 days): Follicular phase, Ovulation (Day $14$ [LH surge]), Luteal phase (Corpus luteum), Menstruation.\n* Contraception:\n * Barrier: Condoms (STI protection), Diaphragm.\n * Non-barrier: Oral pills, IUD (Copper/Hormonal), Implants (3-year rod), Injections (Depo-Provera), Post-pill (emergency), Sterilization (Vasectomy/Tubal ligation).\n* STIs/HIV:\n * Bacterial: Syphilis ($Treponema \\, pallidum$), Gonorrhea, Chlamydia.\n * Viral: HIV (attacks CD4 cells; AIDS stage is $<200 \\, cells/mm^3$), HPV (warts/cancer), Hepatitis B.\n * Parasitic: Trichomoniasis, Scabies (mites), Pubic lice.\n* Substance Effects: Alcohol (cirrhosis, brain damage); Khat (Cathinone stimulant; causes hypertension and oral cancer); Marijuana/Cocaine/Heroin (heart and lung hazards).\n\n# UNIT SIX: POPULATION AND NATURAL RESOURCES\n\n## POPULATION ECOLOGY\n\n* Measurement: Quadrat (for immobile species) and Mark-Recapture (for mobile animals).\n * Quadrat Formula: $N = \\frac{A}{a} \\times n$\n * Mark-Recapture Formula: $N = \\frac{M \\times n}{X}$\n* Dispersal Patterns: Uniform, Random, Clumped.\n* Growth Models:\n * Exponential: J-shaped; unlimited resources. Formula: $dN/dt = r_{max}N$.\n * Logistic: S-shaped; accounts for Carrying Capacity ($K$). Formula: $dN/dt = rN \\frac{K - N}{K}$.\n* Survivorship Curves: Type I (Humans; low early death), Type II (Birds; constant), Type III (Plants/Fish; high early death).\n\n## NATURAL RESOURCES AND ENVIRONMENT\n\n* Types: Renewable (Solar, Wind, Biomass) and Non-renewable (Coal, Oil, Natural gas).\n* Wildlife Conservation Areas in Ethiopia: $24$ National Parks (e.g., Simien Mountains, Bale Mountains), Sanctuaries (e.g., Babile Elephant), and Reserves.\n* Environmental Threats:\n * Pollution: Air (CFCs, $SO_2$, $CO$), Water (Wastes, Eutrophication via Water Hyacinth).\n * Climate Change: Greenhouse gases (CO2, Methane) trapping heat.\n * Ozone Depletion: CFCs breaking $O_3$ into $O_2 + O$.\n * Acid Rain: Formulas: \n $2SO_2 (g) + O_2 (g) + 2H_2O (l) \\rightarrow 2H_2SO_4 (aq)$ \n $4NO_2 (g) + O_2 (g) + 2H_2O (l) \\rightarrow 4HNO_3 (aq)$\n * Toxic Bioaccumulation: Conc. of PBTs (like DDT/Mercury) increase at higher trophic levels.\n* Indigenous Practices (Ethiopia):\n * Konso: Terracing, Contour ploughing, Crop rotation, Mixed cropping, Mulching, Agro-forestry (Moringa).\n * Guassa Area: \"Qero\" community management system for sustainable grazing.", "title": "Biology Grade 11 Comprehensive Study Notes"}