All living things on Earth are made of cells. Based on the number of cells they possess, organisms are divided into two main categories: Unicellular and Multicellular.
Unicellular: Single cell (Amoeba, Bacteria).
Multicellular: Many cells (Humans, Plants).
Division of Labour: Only present in multicellular organisms.
Complexity: Unicellular are simple; Multicellular have complex organ systems.
| Feature | Unicellular | Multicellular |
|---|---|---|
| Cell count | Only one cell | Many cells |
| Size | Microscopic | Macroscopic (visible to naked eye) |
| Role of Cell | One cell does everything | Cells are specialized (Heart, Brain) |
| Lifespan | Short | Long |
Unicellular organisms consist of a single cell that performs all life functions. Multicellular organisms consist of many specialized cells grouped into tissues and organs to perform different functions.
Amoeba and Bacteria are examples of unicellular organisms.
What are Shrubs? Definition and Plant Names
Learn what shrubs are in plant biology. Find a list of common shrub plant names (like Rose, Lemon, and Tulsi) and understand how they differ from herbs.
Difference Between Signs and Symptoms
Learn the exact difference between a Sign and a Symptom in medicine. Understand objective vs subjective evidence of a disease with clear examples.
Difference Between Simple Leaf and Compound Leaf
Learn the difference between a Simple Leaf and a Compound Leaf in botany. Understand the lamina, incisions, leaflets, and clear examples like Mango and Neem.
Simple Permanent Tissue (Parenchyma, Collenchyma, Sclerenchyma)
Learn about Simple Permanent Tissue in plants. Understand the differences between Parenchyma, Collenchyma, and Sclerenchyma cells.
What is the Smallest Cell in the Human Body?
Learn which is the smallest cell in the human body. Discover why the sperm cell is the smallest and why the nerve cell (neuron) is the longest.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.