Object-Oriented Programming (OOP) is a programming paradigm based on "objects" that contain data and code. The four main principles are: **1. Encapsulation**: Bundling data and methods that work on that data within one unit (class) **2. Inheritance**: Creating new classes based on existing ones, inheriting their properties and methods **3. Polymorphism**: Objects of different types can be treated as instances of the same type through a common interface **4. Abstraction**: Hiding complex implementation details and showing only essential features OOP is important because it promotes code reusability, modularity, easier maintenance, and better organization of complex programs.

Photosynthesis is the process by which plants convert light energy into chemical energy (glucose). It occurs in two main stages: **Light Reactions (in thylakoids)**: - Input: Light, water (H₂O), ADP, NADP⁺ - Process: Chlorophyll absorbs light, water is split - Output: Oxygen (O₂), ATP, NADPH **Dark Reactions/Calvin Cycle (in stroma)**: - Input: CO₂, ATP, NADPH from light reactions - Process: Carbon fixation and reduction - Output: Glucose (C₆H₁₂O₆) Overall equation: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂ + 6H₂O

The quadratic formula is x = (-b ± √(b²-4ac)) / 2a. Here's how to use it step by step: 1) Identify coefficients a, b, and c from your equation ax² + bx + c = 0. 2) Substitute these values into the formula. 3) Calculate the discriminant (b²-4ac). 4) Solve for both possible values using + and - in the ± symbol. For example, with x² - 5x + 6 = 0: a=1, b=-5, c=6. Using the formula: x = (5 ± √(25-24))/2 = (5 ± 1)/2, so x = 3 or x = 2.