Cell The Unit of Life - Biology Short Handwritten Notes [PDF]📚

Cell The Unit of Life - The Cell Theory

➡️ All living things are made of cells.

➡️ The cell is the basic unit of structure and function in living organisms.

➡️ All cells arise from pre-existing cells (stated by Rudolf Virchow).

Cell The Unit of Life - Basic Cell Structure

➡️ Cell Membrane: Controls what enters and leaves the cell.

➡️ Nucleus: Contains genetic material (DNA) and directs cell activities.

➡️ Cytoplasm: Jelly-like substance where most cellular activities occur.

➭ Organelles: Specialized structures with specific functions, like:

1. Mitochondria: Powerhouse of the cell, produces energy.
2. Ribosomes: Protein builders.
3. Endoplasmic Reticulum: Transports materials and helps with protein synthesis.
4. Golgi apparatus: Packages and distributes materials.
5. Lysosomes: "Digestive system" of the cell, breaks down waste.

Cell The Unit of Life - Types of Cells

➭ Prokaryotic Cells: Simpler cells, lack a nucleus and membrane-bound organelles (e.g., bacteria).

➭ Eukaryotic Cells: More complex cells, have a nucleus and membrane-bound organelles (e.g., animal and plant cells).

Cell The Unit of Life - Cell Functions

➡️ Growth and Development: Cells increase in size and number.

➡️ Nutrition: Cells take in nutrients and use them for energy and growth.

➡️ Metabolism: Chemical reactions that break down and build up molecules.

➡️ Respiration: Cells use oxygen to release energy from food.

➡️ Excretion: Removal of waste products.

➡️ Reproduction: Cells divide to create new cells.

Cell The Unit of Life - Additional Notes