Specialised cells
Differentiation
As a cell matures it , developing the specific subcellular structures it needs to do its job well. Most animal cells differentiate early in life and stay specialised from then on. Most plant cells keep the ability to differentiate throughout the plant's life, in tissue called .
Because a specialised cell's structure is adapted to its function, you should be able to link each feature below to the job the cell does.
Key terms
Sperm and nerve cells
A has a long tail (flagellum) to swim towards an egg, many mitochondria to release the energy needed to swim, and an at its head, storing enzymes that digest through the egg's membrane.
A is long, to carry electrical impulses over long distances around the body, and has branched connections at each end to link up with many other nerve cells. Many are covered in a fatty , which insulates the cell and speeds up the impulse.
Key terms
Muscle and root hair cells
A contains protein fibres that can contract (shorten), and has many mitochondria to release the energy this needs.
A , found on plant roots, has a long hair-like extension that greatly increases its surface area. This lets it absorb water and mineral ions from the soil more efficiently.
Key terms
Xylem and phloem
tissue is made of dead, hollow cells strengthened with a substance called . It transports water and dissolved mineral ions up the plant, and helps support the stem.
tissue is made of living cells arranged in columns, connected end to end through perforated . It transports dissolved sugars made in the leaves to the rest of the plant — a process called — in both directions.