Specialised Cells

Plant, Bacterial and Animal cells are typical cells, most cells are specialised for a particular function, so…

their function can vary

Multicellular organisms

Contains lots of different types of cells (i.e. cells with different structures)

Specialised cells

Cells which have developed certain characteristics (known as adaptations) in order to perform particular functions

Cells specialise by undergoing differentiation:

• A process by which cells develop the structure and characteristics needed to be able to carry out their functions

Egg cells and Sperm cells are specialised for…

reproduction

Egg cells

Its main function is to carry the female DNA and to nourish the developing embryo in the early stages

How its adapted to its function:

• Contains nutrients in the cytoplasm to feed the embryo

• Haploid nucleus

• Straight after fertilisation, its membrane changes structure to stop any sperm getting in. This makes sure the offspring end up with the right amount of DNA

Sperm cells -

Transports the male’s DNA to the female’s egg

How its adapted to its function:

• Has a long tail so it can swim to the egg

• Has a lot of mitochondria in the middle section to provide the energy (from respiration) needed to swim this distance

• Has an acrosome at the front of the ‘head’ containing enzymes that help the sperm penetrate the egg's outer layers during fertilization

• Contains a haploid nucleus

Ciliated Epithelial Cells

Specialised for moving materials

• Lines the surfaces of organs

• Some of them have cilia (hair-like structures) on the top surface of the cell

• Its function is to move substances - the cilia beat to move substances in one direction, along the surface of the tissue

• e.g. the lining of the airways contains lots of this to help move mucus (and all the particles from the air it has trapped) up to the throat so it can be swallowed and doesn’t reach the lungs