Unit C Review

Unit C Review Key Concepts

Chapter C1: Microscopy

• Scientists – Contributions to Microscopy / Cell Theory

  • Janssens: Contributed to the early development of microscopy.

  • Hooke: Discovered cells; coined the term "cell" after observing cork.

  • Van Leeuwenhoek: First to observe live cells; improved lens quality.

  • Redi: Pioneered experimental techniques; debunked spontaneous generation.

  • Needham: Supported the idea of spontaneous generation through broth experiments.

  • Spallanzani: Disproved Needham; emphasized the need for sealing and heating to prevent contamination.

  • Pasteur: Confirmed that microorganisms cause disease; introduced pasteurization.

  • Brown: Discovered the nucleus in plant cells.

  • Schleiden & Schwann: Developed the cell theory, stating all living things are composed of cells.

• Cell Theory

  • All living organisms are composed of one or more cells.

  • Cells are the basic unit of life.

  • All cells arise from pre-existing cells.

• Parts of the Microscope

  • Eyepiece, objective lenses, stage, light source, diaphragm, etc.

• Microscopy Skills

  • Calculating Magnification: Multiply the eyepiece and objective lens magnification.

  • Measuring Field of View (low power): Determine the visible area of the specimen.

  • Calculating Field of View (high power): Apply the formula to find dimensions at high power.

  • Calculating Actual Size: Use the field diameter and proportion of the specimen size.

  • Calculating Scale: Relate size on the image to the actual dimensions.

  • Unit Conversion: Converting mm to µm (1 mm = 1000 µm).

• Advancements in Microscopy

  • Magnification, Resolution, Contrast: Key factors in improving microscopy.

  • Light Microscopes vs. Electron Microscopes: Light allows viewing of live specimens; electron provides high resolution but requires specimens to be non-living.

  • Applications in Industry & Medicine: Includes diagnostics, research, and quality control.

Chapter C2: Cells

• Organelles – Structure/Function

  • Differences Between Animals and Plants: Plants have cell walls and chloroplasts, while animals do not.

• Photosynthesis, Cellular Respiration, Energy Storage

  • Chemical Reactions: Essential metabolic processes.

  • Molecules Used by the Cell: Glucose and other carbohydrates used for storage.

• Fluid Mosaic Model

  • Cell Membrane as Phospholipid Bilayer: Comprises hydrophilic heads and hydrophobic tails.

  • Role in Cell Communication & Transport: Facilitates substance movement in and out of cells.

• Transport Mechanisms

  • Diffusion: Movement from high to low concentration without energy.

  • Osmosis: Selective movement of water across a semi-permeable membrane.

  • Facilitated Diffusion: Movement through specific channel proteins.

  • Active Transport: Movement against concentration gradient requiring energy (ATP).

  • Endocytosis/Exocytosis: Processes for internalization and secretion of substances.

• Tonicity and Its Impact on the Cell

  • Applications in Industry & Medicine: Importance in therapeutic contexts.

• Surface Area to Volume Ratios

  • Implications of Multicellularity: Efficient transport and resource allocation.

  • Calculations – What the Numbers Mean: Essential for understanding cell function limitations.

Chapter C3: Plants

• Organization of a Multicellular Organism

  • Cells, Tissues, Organs, Systems: Hierarchical structure in multicellular organisms.

• Structure & Function of Plant Tissues

  • Dermal Tissue: Upper and lower epidermis protect the plant.

  • Ground Tissue: Palisade layer (photosynthesis) & spongy mesophyll (gas exchange).

  • Xylem & Phloem: Transport water and nutrients.

• Control Systems in Plants

  • Opening and Closing the Stoma: Regulation of gas exchange.

  • Phototropism: Growth towards light; influenced by auxin.

  • Gravitropism: Response to gravity; roots grow down, shoots grow up.

• Transport in Plants

  • Root Pressure: Pushes water upwards.

  • Cohesion & Adhesion: Water molecules link and cling to surfaces.

  • Transpirational Pull: Evaporation creates a vacuum effect for water transport.

  • Pressure-Flow Theory: Explains nutrient transport in phloem.