Biology: Exploring Life Chapter 1 - 2A PDF

Sure! Here’s a structured summary of the key concepts from your chapters. ### Chapter 1 – Biology: Exploring Life #### Definitions - **Science**: A systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. - **Biology**: The...

Sure! Here’s a structured summary of the key concepts from your chapters. ### Chapter 1 – Biology: Exploring Life #### Definitions - **Science**: A systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. - **Biology**: The study of life and living organisms. #### Scientific Method Steps 1. Observation 2. Question 3. Hypothesis 4. Experimentation 5. Analysis 6. Conclusion 7. Communication - **Good Hypothesis**: Testable and falsifiable statement that predicts an outcome. - **Theory**: A well-substantiated explanation of some aspect of the natural world, based on a body of evidence. #### Properties of Life (7) 1. Order 2. Sensitivity to stimuli 3. Reproduction 4. Adaptation 5. Growth and development 6. Regulation 7. Homeostasis #### Hierarchy of Life - **Atom**: Smallest unit of matter (e.g., carbon). - **Molecule**: Two or more atoms bonded together (e.g., water). - **Organelle**: Specialized structure within a cell (e.g., mitochondria). - **Cell**: Basic unit of life (e.g., skin cell). - **Organism**: Individual living entity (e.g., human). #### Macromolecules (4 Types) 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids #### Cell Types - **Prokaryotic**: No nucleus, simple structure (e.g., bacteria). - **Eukaryotic**: Nucleus and complex organelles (e.g., plant and animal cells). #### Tissues (4 Types) 1. Epithelial: Covers body surfaces and lines cavities. 2. Connective: Supports and binds other tissues (e.g., bone, blood). 3. Muscle: Responsible for movement (e.g., skeletal, cardiac). 4. Nervous: Transmits signals (e.g., neurons). #### Definitions - **Population**: Group of the same species in a given area. - **Community**: Different populations living together. - **Ecosystem**: Community plus its abiotic environment. - **Biosphere**: Global sum of all ecosystems. - **Biotic**: Living components. - **Abiotic**: Non-living components. #### Energy Acquisition - **Autotrophs**: Produce their own food (e.g., plants). - **Heterotrophs**: Consume others for energy (e.g., animals). - **Saprotrophs**: Decompose organic matter (e.g., fungi). #### Taxonomy and Evolution - **Taxonomy**: Science of classifying organisms. - **Phylogenetic System**: Classification based on evolutionary relationships. - **Scientific Name**: Binomial nomenclature (genus + species). - **Five Kingdoms**: Monera, Protista, Fungi, Plantae, Animalia. - **Evolution**: Change in the heritable characteristics of biological populations over generations. #### Charles Darwin - Proposed the theory of evolution by natural selection; authored "On the Origin of Species." #### Four Postulates of Natural Selection 1. Variation exists within populations. 2. Variations are heritable. 3. More offspring are produced than can survive. 4. Those with favorable traits are more likely to survive and reproduce. - **Adaptation**: A trait that enhances survival and reproduction. --- ### Chapter 2A – The Chemistry of Life #### Definitions - **Matter**: Anything that has mass and occupies space (solid, liquid, gas). - **Mass**: Amount of matter in an object (grams). - **Volume**: Space occupied by matter (liters). - **Elements**: Pure substances that cannot be broken down (e.g., oxygen). - **Essential Elements**: Elements required for life (e.g., carbon, hydrogen). - **Macronutrient**: Required in large amounts (e.g., carbohydrates). - **Trace Element**: Required in small amounts (e.g., iron). - **Compound**: Two or more elements chemically combined. #### Subatomic Particles - **Proton**: Positive charge. - **Neutron**: No charge. - **Electron**: Negative charge. #### Atomic Concepts - **Atomic Number**: Number of protons. - **Atomic Mass**: Number of protons + neutrons. - **Isotope**: Atoms with the same number of protons but different neutrons. - **Electron Shells**: - 1st shell: 2 electrons. - 2nd shell: 8 electrons. - 3rd shell: 18 electrons. - **Valence Shell**: Outermost shell involved in chemical reactions. #### Chemical Bonds - **Ionic Bond**: Transfer of electrons. - **Covalent Bond**: Sharing of electrons. - **Valence**: Combining capacity of an atom. - **Double Bond**: Two pairs of shared electrons. - **Electronegativity**: Atoms' ability to attract electrons. - **Hydrogen Bonds**: Weak bonds between polar molecules. #### Bond Polarity - **Polar Covalent Bond**: Unequal sharing of electrons (e.g., H₂O). - **Nonpolar Covalent Bond**: Equal sharing (e.g., H₂, O₂, CH₄). #### Properties of Water - **Polarity**: Oxygen is slightly negative, hydrogens are slightly positive. - **Cohesion**: Water molecules stick together; creates surface tension. - **Temperature Stability**: High specific heat. - **Density**: Ice is less dense than liquid water. - **Solvent Properties**: Universal solvent for polar substances. #### pH Scale - Ranges from 0 (acidic) to 14 (basic); 7 is neutral. - **Example of Acid**: HCl (hydrochloric acid). - **Example of Base**: NaOH (sodium hydroxide). --- ### Chapter 2A – Macromolecules #### Definitions - **Macromolecule**: Large molecules made of smaller subunits. - **Monomer**: Small building block (e.g., glucose). - **Polymer**: Long chain of monomers (e.g., starch). #### Synthesis and Breakdown - **Dehydration Synthesis**: Process of joining monomers by removing water. - **Hydrolysis**: Breaking down polymers by adding water. #### Carbohydrates - **Monomer**: Monosaccharide (e.g., glucose). - **Polymer**: Polysaccharide (e.g., starch, glycogen, cellulose, chitin). - **Glycosidic Bond**: Link between carbohydrates. #### Lipids - **Nonpolar and Hydrophobic**: Do not mix with water. - **Monomer**: Glycerol and fatty acids. - **Polymer**: Triglycerides. - **Saturated vs Unsaturated Fats**: Saturated have no double bonds; unsaturated have one or more. - **Trans Fats**: Artificially hydrogenated fats. - **Essential Fatty Acids**: Necessary fats not synthesized by the body. - **Phospholipid Bilayer**: Composes cell membranes. #### Proteins - **Types & Functions**: Structural, enzymes, transport, etc. - **Monomer**: Amino acid. - **Peptide Bond**: Bond between amino acids. - **Polymer**: Polypeptides. #### Nucleic Acids - **Examples**: DNA, RNA. - **Monomer**: Nucleotide (consists of a sugar, phosphate group, nitrogenous base). - **Polymer**: Polynucleotide (DNA and RNA strands). - **DNA vs RNA**: DNA is double helix; RNA is single-stranded. --- ### Chapter 3 – Cell Structure and Function #### Microscopy Concepts 1. Magnification 2. Resolution 3. Contrast #### Types of Microscopes - **Light Microscopes**: Compound and stereo microscopes. - **Electron Microscopes**: Transmission (TEM) and scanning (SEM). #### Cell Theory 1. All living things are composed of cells. 2. Cells are the basic unit of life. 3. All cells come from pre-existing cells. #### Comparison of Cells - **Prokaryotic Cells**: Smaller, no nucleus, simpler structure. - **Eukaryotic Cells**: Larger, with a nucleus and organelles. #### Organelle Functions - **Plasma Membrane**: Selectively permeable barrier. - **Cytoplasm**: Gel-like substance where organelles reside. - **Cilia & Flagella**: Movement. - **Nucleus**: Houses genetic material. - **Nucleolus**: Produces ribosomes. - **Ribosomes**: Protein synthesis. - **Endoplasmic Reticulum**: Synthesizes proteins and lipids (rough and smooth). - **Golgi Apparatus**: Modifies, sorts, and packages proteins. - **Chloroplast**: Photosynthesis (in plants). - **Mitochondria**: Energy production (ATP). - **Lysosomes**: Digests waste materials. - **Peroxisomes**: Breaks down fatty acids and detoxifies. - **Vacuoles**: Storage (central in plants). - **Cell Wall**: Provides structure and protection (in plants). - **Centrioles**: Involved in cell division. 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