What are the main differences between plant and animal cells?

Plant and animal cells are both based on eukaryotic systems, but they show marked structural and functional differences. Plant cells have a *cell wall* that is made of cellulose and is rigid for mechanical support. In contrast, animal cells have a flexible *extracellular matrix* to support them. The most obvious difference is the presence of *chloroplasts* in plant cells, which are the organelles responsible for photosynthesis, a process entirely lacking in animal cells. In addition, the plant cells have a *large vacuole*, which can occupy 90% of the total volume, acting as a storage organ and helping maintain cell turgor. Still, animal cells have several small vacuoles. These differences result from millions of years of divergent evolution, which have allowed them to fulfill different ecological functions.

Differences in organelles also lead to functional diversity. In the case of plants, centrioles, lysosomes, and several other structures common to animal cells are lacking. Dependence on plasmodesmata is another example of unique plant structural features that allow for direct cell-to-cell communication. In animals, gap junctions serve this purpose. Metabolic activities also vary greatly. For example, plants store excess sugar as starch granules, which are found in chloroplasts or amyloplasts. Still, in animals, it is stored as glycogen deposits in liver and muscle cells. Such metabolic differences are indications of each kingdom's adaptations to suit their means of nutrition, with plants as producers and animals as consumers.

These differences in cellular structure have tremendous ecological consequences. The walls of plant cells provide substantial strength to resist compression, allowing trees to grow vertically to heights in excess of 100 m. On the other hand, the flexible structure of animal cells accommodates locomotion and the formation of complex tissues. The chloroplasts contribute to the oxygenation of the atmosphere as a byproduct of photosynthesis and thus have played a major role in the development of the land-formed biosphere. The central vacuoles in plant cells allow the plants to survive periods of environmental stress, such as drought, by assisting in the maintenance of turgor pressure. Knowledge of the blueprints for these different cellular types can aid in developing agricultural innovations in biomaterials, as well as in creating conservation programs that address the specific weaknesses of each of these kingdoms in relation to the proposed and implemented environmental alterations.

Read the full article: Plant Cell Structure: A Comprehensive Guide