Imagine a city. It has buildings, roads, and various systems for transportation, electricity, and water. In the same way, multicellular organisms, like us humans, have a hierarchy of organization that works together to keep everything running smoothly.

• Basic unit of life.
• Specialized to do specific jobs.
• Example: Think of a cell as an individual house or building in a city. Each building has its own purpose, like a school, a store, or a home.

• Groups of similar cells working together.

• Tissues can have multiple cell types.

  For instance, let's dive into the world of lungs: 🌬️

  • AT1 cells
    • 95% of the respiratory surface.
    • Super thin – like the walls of a transparent house.
    • Role: Gas exchange.
  • AT2 cells
    • Look more like cubes packed with stuff inside.
    • Role: Secret superheroes! They make a substance to keep alveoli open.

  🌱 Fun fact: Plant cells are like best buddies holding hands – they stick together with a gluey substance called pectin.

  🐾 For animals, cells are like LEGO pieces connected with special proteins.

  💉 But, remember, not all tissues stick - like blood. Blood cells are like free birds; they float around without sticking to each other!