Cell differentiation: Students should be able to explain the importance of cell differentiation.

The idea

Cell differentiation is the process by which a cell becomes specialised for a particular job. It happens because different genes in the cell are switched on or off, so the cell makes only the proteins it needs. Differentiation is important because it produces cells with shapes and features suited to specific functions, such as a sperm cell with a tail for swimming or a red blood cell with no nucleus and a biconcave shape for carrying oxygen. In multicellular organisms, differentiated cells work together as tissues, organs and organ systems, allowing the organism to carry out life processes efficiently. In most animal cells, differentiation is permanent, whereas many plant cells retain the ability to differentiate throughout life.

What earns the marks

• Differentiation is the process by which a cell becomes specialised for a particular function.
• Differentiation occurs because different genes are switched on or off, so each cell produces the proteins needed for its job.
• Differentiated cells have structures suited to their function, such as a sperm cell tail or a red blood cell biconcave shape.
• Differentiation allows cells to form tissues, organs and organ systems that carry out life processes efficiently.
• Most animal cells differentiate permanently, while many plant cells can differentiate throughout life.

Common mistakes and how to put them right

• Saying differentiation changes the genes a cell contains.

  Put it right by stating the genes stay the same but different genes are switched on or off.

• Confusing differentiation with cell division.

  Put it right by stating division makes more cells, while differentiation makes cells specialised.

• Claiming all cells differentiate at the same time.

  Put it right by stating differentiation happens at different times and some cells, such as many plant cells, retain the ability throughout life.

Exam tips

• Define differentiation clearly before explaining why it matters.
• Use named examples such as sperm cells, red blood cells or root hair cells to support each point.
• Link differentiation to the hierarchy of cells, tissues, organs and organ systems.