Introduction to Biology, Cells, Classification, The Five Kingdoms of Living Organisms, Insects, Flowering Plants

Topic 1.1: Introduction to Biology

* **Definition:** The scientific study of life and living organisms (from Greek *bios* = life, *logia* = study). * **Branches:** Botany (plants), Zoology (animals), Physiology (functions), Anatomy (structure), Genetics (heredity/variation), Ecology (interactions), and Taxonomy (classification). * **Life Processes (MR NIGER D):** Movement, Respiration, Nutrition, Irritability (Sensitivity), Growth, Excretion, Reproduction, and Death.

Topic 1.2: Cells

* **Definition:** The fundamental structural and functional unit of life. * **Organelles:** * **Shared:** Cell membrane, cytoplasm, nucleus, mitochondria (aerobic respiration). * **Plant-only:** Cell wall (cellulose), chloroplasts (photosynthesis), large central vacuole. * **Specialized Cells:** Red blood cells (oxygen transport), Nerve cells (impulses), Root hair cells (absorption), Sperm cells (locomotion). * **Levels of Organization:** Cell → Tissue → Organ → System → Organism.

Topic 1.3: Classification

* **Hierarchy:** Kingdom, Phylum, Class, Order, Family, Genus, Species (Mnemonic: *King Philip Came Over For Good Spaghetti*). * **Binomial Nomenclature:** Universal naming system (Genus species) using Latin; genus capitalized, species lowercase. * **Five Kingdoms:** * **Monera:** Prokaryotic, unicellular (e.g., Bacteria). * **Protoctista:** Eukaryotic, mostly unicellular (e.g., Amoeba). * **Fungi:** Eukaryotic, chitin cell walls, saprotrophic/parasitic (e.g., Mushrooms). * **Plantae:** Eukaryotic, cellulose cell walls, autotrophic (e.g., Flowering plants). * **Animalia:** Eukaryotic, no cell wall, heterotrophic (e.g., Mammals).

Topic 1.4: Insects

* **Features:** Three body parts (Head, Thorax, Abdomen), six legs, antennae, compound eyes. * **Dichotomous Key:** A system of paired choices used for identification. * **Effects:** Pollination (useful) vs. Disease transmission (e.g., Mosquitoes, Houseflies) and crop destruction (harmful).

Topic 1.5: Flowering Plants

* **Reproductive Parts:** * **Stamen (Male):** Anther (produces pollen), Filament. * **Pistil/Carpel (Female):** Stigma (receives pollen), Style, Ovary (contains ovules). * **Process:** Pollination (transfer of pollen) → Fertilization (fusion of gametes) → Ovule becomes Seed, Ovary becomes Fruit.

---

<!-- keywords: MR NIGER D, Prokaryotic, Eukaryotic, Binomial Nomenclature, Carolus Linnaeus, Vascular Plants, Angiosperms, Gymnosperms, Dichotomous Key, Pollination, Fertilization, Taxonomy, Cellular Respiration, Organelles, Differentiation -->