Biology Review

Section 1: Microscopes, Cell Theory, Imaging Technology, Staining, Cell Research

Jansen Brothers: Invented the first microscope.
Robert Hooke: Observed cork under a microscope and named the structures "cells."
Van Leeuwenhoek: First to observe living microorganisms and noted their movement.
Compound Light Microscope: Type of microscope used in the lab for observations.

Total Magnification Formula:
- Total Magnification = Eyepiece Magnification x Objective Lens Magnification.

Scale Definition: The ratio between the size of a diagram and the actual size of the object.
Actual Size Calculation:
- Actual Size = (Field Diameter / Number of objects that fit across the field of view).
Scale Calculation:
- Scale = (Diagram Size of Objects (units) / Actual Size (units)).
- Ensure both measurements use the same units (e.g., mm to mm, µm to µm).

Contrast with Spontaneous Generation: Modern cell theory denies spontaneous generation.
Three Essential Tenets of Cell Theory:
- All living things are made of cells.
- Cells are the basic units of life.
- Cells arise from pre-existing cells via cell division.

Staining: Adds dye to cells to enhance contrast for better visualization of details and structures.
Advanced Microscopes: Transmission and electron scanning microscopes offer higher magnification and detail visibility.

Section 2: Focus on Cell Membrane, Cell Transport, and Surface Area: Volume Ratio.

Key Concepts:
- Diffusion: Movement of particles from an area of high concentration to low concentration.
- Osmosis: Diffusion of water across a selectively permeable membrane.
- Facilitated Diffusion: Movement of molecules across a membrane via transport proteins.
- Active Transport: Movement of substances against their concentration gradient, requiring energy.
- Passive Transport: Movement of substances down their concentration gradient without energy.
- Endocytosis: Process of taking materials into the cell by engulfing them.
- Exocytosis: Process of expelling materials from the cell.
- Solutions: Hypertonic, hypotonic, and isotonic solutions impact cell dynamics.

Section 3: Study of Leaf Structure and Functions, Photosynthesis, Gas Exchange, Transport Systems, Control Systems

Key Features:
- Epidermis: Protective outer layer of the stem.
- Vascular Bundles: Contain xylem and phloem for nutrient and water transport.
- Pith: Tissue in the center of the stem.
- Cortex: Located between the epidermis and vascular bundles.

Reaction: 6CO2 + 12H2O → C6H12O6 + 6O2 + 6H2O (Produces glucose from carbon dioxide and water, facilitated by light and enzymes.)

Reaction: C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP) (Process of breaking down glucose to release energy.)

Key Processes:
- Guard cells regulate stomatal opening.
- Stomata can be open or closed depending on guard cell turgidity (hydration state).

Cohesion: Water molecules' attraction to each other.
Adhesion: Water molecules' attraction to other substances.
Root Pressure: Upward force exerted in xylem from roots.
Transpiration: Evaporation from leaves, helping to draw water up from roots.To