Plant Cells Vs. Animal Cells (With Diagrams)

Cells have often been referred to as "the building blocks of life," and indeed they are.

All forms of life, from simple bacteria to human beings, are made up of cells. What is remarkable is that, despite their differences in appearance, plant and animal life are made up of cells that are the same in most respects.

In both animals and plants, cells generally become specialized to perform certain functions. Nerve cells, bone cells and liver cells, for example, all develop in ways that enable them to better perform their specific duties.

The most important structures of plant and animal cells are shown in the diagrams below, which provide a clear illustration of how much these cells have in common. The significant differences between plant and animal cells are also shown, and the diagrams are followed by more in-depth information.

Plant cells have to perform two functions that are not required of animal cells:

1. Produce their own food (which they do in a process called photosynthesis).
2. Support their own weight (which animals usually do by means of a skeleton).

The structures possessed by plant cells for performing these two functions create the primary differences between plant and animals cells. These structures are:

Structures Unique to Plant Cells

• Cell Wall: A wall on the outside of the membrane, which, in combination with the vacuole (as described below), helps the plant cell maintain its shape and rigidity.
• Plastids: Used in photosynthesis to convert sunlight, carbon dioxide, and water into food. The most well-known plastids are chloroplasts, which contain the chlorophyll that gives many plants their green hue.
• Large Vacuole: While animal cells may have many tiny vacuoles, a plant cell usually has a single large vacuole, which serves as a storage tank for food, water, waste products, and other materials. The vacuole has an important structural function, as well. When filled with water, the vacuole exerts internal pressure against the cell wall, which helps keep the cell rigid. A plant that is wilting has vacuoles that are no longer filled with water.

While animal cells do not have a cell wall, chloroplasts, or a large vacuole, they do have one component plant cells do not. This is:

Structures Unique to Animal Cells

• Centrioles: Animal cells contain organelles known as centrioles, which are not present in plant cells. Centrioles help move chromosomes during cell division. Since animal cells are softer than plant cells, centrioles are required to ensure the chromosomes are in the proper location when the cell divides. Plant cells, with their more fixed shape, can safely assume that the chromosomes are correctly positioned.

Both plant cells and animal cells are Eukaryotic cells. These are cells that contain a well-defined nucleus and in which the other organelles are held together by membranes.

What Is an Organelle?

An organelle is any specialized structure that is contained within a cell. Organelles perform various functions to keep the cell alive.

Organelles that can be found in both plant and animal cells include the following:

As hard as it may be to imagine, biologists believe that at an early point in the evolution of life on Earth, plants and animals once shared a common ancestor. All life on Earth, it seems, is truly related.

• Wallace, Holly. Cells And Systems. Chicago: Heinemann Library, 2006.
• Phenlan, Jay. What Is Life? A Guide to Biology. New York: W.H. Freeman and Company, 2010.
• Exams India. Differences Between Plant and Animal | Cell Procaryotic and Eucaryotic Cell 2012. http://examsindia.net/2010/01/differences-between-plant-and-animal-cell-procaryotic-and-eucaryotic-cell.html