By Maria Cook, updated Mar 24, 2022
Plants and animals are both cellular life forms, but their cells diverge in structure, protein synthesis, and differentiation potential. Understanding these distinctions sheds light on how each kingdom thrives.
Plant cells are encased in a rigid cell wall composed of cellulose, providing support and protection. Animal cells rely on a flexible plasma membrane, enabling easier transport of molecules.
Because plant cells are largely stationary, they typically lack cilia and flagella. In contrast, many animal cells possess cilia or flagella for locomotion and environmental sensing.
Centrioles, cylindrical organelles involved in spindle formation during mitosis, are common in animal cells but absent in most plant cells. Plants instead use cortical microtubules guided by their cell wall architecture.
Plastids—organelles such as chloroplasts—are unique to plant cells. Chloroplasts contain chlorophyll, enabling photosynthesis, a process absent in animal cells.
Both plant and animal cells synthesize proteins essential for growth and function. Plants contain all 20 standard amino acids within their metabolism, allowing them to build proteins de novo.
Animals, however, synthesize only 10 of the 20 essential amino acids; the remaining 10 must be obtained from the diet. This dietary dependence reflects the diverse nutrient acquisition strategies of animals versus plants.
In plants, many differentiated cells can revert or transform into other cell types during growth or repair. For example, a cell in the epidermis can divide and become a mesophyll cell with a distinct role.
Animals rely primarily on stem cells for differentiation. Most mature animal cells are terminally differentiated, capable of division only to replace themselves or repair tissue, but not to become a different cell type.
These fundamental differences underscore the divergent evolutionary paths of plants and animals, influencing everything from development to ecological interactions.
— Maria Cook
