Cell specialisation refers to the process where cells take on specific tasks. Most cells in the body have specific functions. The structure of a cell, including its shape and components, determines its role. Therefore, specialised cells may look very different from each other based on their unique functions.
In order for a cell to carry out its function effectively, it needs to have a structure that complements its role. For example, a red blood cell's biconcave shape allows it to easily transport oxygen and carbon dioxide throughout the body. Similarly, muscle cells have a unique structure that allows them to contract and generate force, enabling movement. Understanding a cell's structure can therefore help us to better interpret its function within an organism.
To better illustrate how cell shape and function are connected, consider the following examples:
1. Sperm cells
2. Nerve cells
3. Muscle cells
4. Root hair cells
5. Phloem and Xylem cells
Sperm cells are specialised in the reproductive process, with the crucial task of transferring male DNA to female DNA. They have a unique structure that helps them achieve this function. The long tail and streamlined head of a sperm cell enable it to swim towards the egg. The cell also has a large number of mitochondria to provide the energy required for movement. Its head contains enzymes that can break down the egg's cell membrane, facilitating fertilization. The picture below illustrates the structure of a sperm cell.
Rapid signalling is a specialty of nerve cells. Thetransmission of electrical information from one area of the body to another isthe job of nerve cells. These cells have branched connections at their ends andare lengthy (to cover more ground) in order to link to other nerve cells andcreate a network throughout the body.
Muscle cells are specialised in the process of muscle contraction, which involves the rapid shortening of the cell. The primary function of a muscle cell is to generate force and movement. To achieve this, muscle cells contain a large number of mitochondria, which transfer the energy required for contraction. The cells themselves are elongated, providing enough space for them to contract effectively. Overall, the unique structure of muscle cells allows them to carry out their function of generating force and movement efficiently.
Root hair cells are specialized cells found on the surface of plant roots that are responsible for absorbing water and nutrients from the soil. They develop into lengthy "hairs" that protrude into the ground, increasing the surface area available to the plant for absorbing water and mineral ions. The dimension of root hair cells ranges between 15-17 μm in diameter and 80-1500 μm in length. The root hair cell is roughly rectangular in shape with a cytoplasmic extension on its lateral end (the root hair). It has a cell wall with intercellular spaces, a semi-permeable cell membrane, and a cytoplasmic extension on its lateral end.
Xylem and phloem are two types of transport tissues found in vascular plants. Xylem is responsible for transporting water and minerals from the roots to the rest of the plant, while phloem transports sugars from the leaves to the rest of the plant. Xylem tissue consists of specialized, water-conducting cells known as tracheary elements, while phloem tissue consists of sieve tubes which have many holes for transporting nutrients. Xylem cells are star-shaped and hollow in the centre, while phloem cells have relatively few subcellular structures.
What is cell specialisation?
A specialised cell is one that performs a specificfunction.
Give 5 examples of specialised cells.
1. Sperm cells
2. Nerve cells
3. Muscle cells
4. Root hair cells
5. Phloem and Xylem cells
How are sperm cells adapted?
It can swim to the egg with the help of its long tailand streamlined head. To supply the energy the cell needs to achieve this, thecell has a large number of mitochondria. Additionally, it has enzymes in itshead that break down the egg's cell membrane so that the egg can be fertilized.
How are root hair cells adapted?
They have a thin cell wall and a very high surface areawhich increases the rate of diffusion through the membrane. They also have avacuole like all plant cells.
