All cells are designed to perform a particular job within an organism, that is, to sustain life.
Cells can become specialized to perform a particular function within an organism, usually as part of a larger tissue consisting of many of the same cells working together for example muscle cells. The cells combine together for a common purpose.
All organisms will contain specialised cells.
There are hundreds of types of specialised cells. Below is listed some of the major ones found in plants and animals.
Plant Cell Specialisation
Guard cells (a pair form a stoma hole) – kidney shapes cells that change shape depending on water content. Regulate the exchange of gases in and out of the plant, and the amount of water lost through the leaves of the plant.
Pollen grains – circular cells with an extremely hard protective cell wall containing sperm cells, pollen grains germinate when they come in contact with female stamens, producing a pollen tube through which the sperm travel to reach the ova (ovary). These pollen tubes can easily be seen in a corn cob.
Root hair cell – designed to increase the surface area of the root for absorption of water and mineral nutrients into the plant. These cells have a very thin cell wall that is fully permeable that allows the absorption of mineral nutrients as ions by cation and anion exchange. Contain large vacuoles for the short term storage of these nutrients.
Epidermal cells – feature a waxy cuticle (covering) to help prevent water loss from the plant, the cells on the top side of the leaf tend to be more waxy due to higher exposure to the elements.
Palisade cell (mesophyll) – designed for photosynthesis, it is a tall cell with a large surface area contained many chloroplasts. Located on top side of the leaf in plants to allow optimum absorption of light and carbon dioxide (inputs for photosynthesis).
Xylem and Phloem cells (combined referred to as vascular bundles) – cells responsible for the transport