What Are Plant and Animal Cells?

Cells: The Building Blocks of Life

Every living organism on Earth — from bacteria to blue whales — is made of cells. Some organisms like bacteria consist of just one cell. Your body, on the other hand, contains roughly 37 trillion cells, all working together. A cell is the smallest unit that can carry out all the functions of life: it takes in nutrients, converts them to energy, carries out specialized tasks, and reproduces. Think of cells as the bricks that build every living structure.

What Both Cell Types Share

Plant cells and animal cells are both eukaryotic — they have a nucleus surrounded by a membrane that holds the cell's DNA (the instruction manual for life). Both types also have a cell membrane that controls what enters and exits the cell, mitochondria that act as power plants converting nutrients into energy, ribosomes that build proteins, and a gel-like cytoplasm filling the cell's interior. These shared features reflect the fact that plants and animals share a common ancestor deep in evolutionary history.

What Makes Plant Cells Different

Plant cells have three major structures that animal cells lack. First, a rigid cell wall made of cellulose surrounds the cell membrane, giving plants their structural strength — it's why a tree trunk can stand tall without bones. Second, chloroplasts are organelles filled with the green pigment chlorophyll, which captures sunlight and converts it into food through photosynthesis. Chloroplasts are why plants are green. Third, plant cells typically have a large central vacuole — a huge, water-filled sac that can take up 90% of the cell's volume, maintaining pressure that keeps the plant upright.

What Makes Animal Cells Different

Animal cells are generally smaller and more irregularly shaped than plant cells (no rigid cell wall to enforce a box shape). They have centrioles — structures that help organize cell division — which most plant cells lack. Animal cells also have many small vacuoles instead of one giant one. Without cell walls, animal cells are more flexible, which is important for animals that need to move, contract muscles, and change shape.

Why This Matters

Understanding cells is the foundation of all biology. When you learn how cells work, you understand why plants need sunlight (chloroplasts), why you need to eat food (no chloroplasts — you can't make your own energy from sunlight), why cuts heal (cell division), and how diseases attack the body (by disrupting cell functions). Every medical breakthrough, from antibiotics to vaccines to cancer treatments, depends on understanding what happens inside cells.

Where Kids Get Stuck

The most common confusion is not understanding what makes a cell "alive." Children know animals and plants are alive, but they struggle to see a single cell as a living thing. Yet every cell takes in nutrients, produces energy, grows, responds to its environment, and can reproduce. A single-celled amoeba does everything a human does — just at a microscopic scale.

Another difficulty is remembering which organelles are in which cell type. The key differences make sense once you understand why: plant cells have chloroplasts because plants make food through photosynthesis. Plant cells have large central vacuoles for water storage. Plant cells have rigid cell walls that give them their boxy shape. Animal cells have only flexible cell membranes, which is why animal tissue is soft and flexible.

Students also think cells are empty inside, like hollow balls. In reality, cells are packed with structures. The cytoplasm contains mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, and many other organelles, all working together like a miniature factory.

Organelles: The Cell's Workforce

Each organelle has a specialized job, and analogies help make them memorable:

• Nucleus — The "brain" or "control center." Contains DNA instructions for everything the cell does.
• Mitochondria — The "power plants." Convert glucose into ATP (energy). Present in both plant and animal cells.
• Ribosomes — The "construction workers." Build proteins by reading instructions from the nucleus.
• Cell membrane — The "security gate." Controls what enters and exits. Present in all cells.
• Cell wall — The "outer fortress." Rigid structure. Only in plant cells.
• Chloroplasts — The "solar panels." Capture sunlight for photosynthesis. Only in plant cells.
• Vacuole — The "storage warehouse." Stores water, nutrients, waste. Much larger in plant cells.

Try This at Home

• Edible cell model — Use gelatin (cytoplasm), a grape (nucleus), sprinkles (ribosomes), fruit roll-ups (membranes), and gummy worms (endoplasmic reticulum) to build a 3D cell.
• Onion skin microscope — Peel thin skin from an onion, place on a slide with iodine, and observe plant cells with visible cell walls and nuclei.
• Egg membrane experiment — Soak a raw egg in vinegar for 48 hours. The shell dissolves, leaving just the membrane. Soak in corn syrup (shrinks) then water (swells) to demonstrate osmosis.
• Cell comparison chart — Draw a Venn diagram comparing plant and animal cells. Shared features in the middle, unique features on each side.

For more hands-on science, see: Free Science Tools for the Classroom.

Last reviewed: May 2026