AQA GCSE Biology- Cell biology 4.1.1.3 ( Cell Specialisation)

What is a specialised cell?

A cell that has a structural adaptation to perform a particular function.

Give 3 examples of specialised cells in animals.

Sperm cells

Nerve cells

Muscle cells

Give 3 examples of specialised cells in plants.

Root Hair cells

Xylem cells

Phloem cells

What are sperm cells specialised for?

They are specialised to carry the male's DNA to the egg cell for reproduction.

Give an adaptation of a sperm cell. (1)

Has a streamlined head and long tail to aid swimming.

Give an adaptation of a sperm cell. (2)

Has lots of mitochondria to supply energy for the cell to move.

Give an adaptation of a sperm cell. (3)

The acrosome (top of the head) has digestive enzymes which break down the outer layer membrane of the egg cell.

What are nerve cells specialised for?

Rapid signalling by carrying electric signals from one part of the body to another.

Give an adaptation of a nerve cell. (1)

Has a long axon which allows the impulses to be carried along long distances.

Give an adaptation of a nerve cell. (2)

Has lots of extension from the cell's body, called dendrites, to form branched connections with other sperm cells.

Give an adaptation of a nerve cell. (3)

The nerve endings have lots of mitochondria to supply energy to make special transmitter chemicals called neurotransmitter. The neurotransmitters allow the impulses to be passed from one cell to another.

What are muscle cells specialised for?

Muscle cells are specialised to contract quickly, causing movement.

Give an adaptation of a muscle cell. (1)

Special proteins called myosin and actin slide over each other, causing the muscle to contract.

Give an adaptation of a muscle cell. (2)

Has lots of mitochondria to provide energy from respiration for contraction.

Give an adaptation of a muscle cell. (3)

Stores a chemical called glycogen that is used in respiration by mitochondria.

What are root hair cells specialised for?

They are specialised to take up water via osmosis and mineral ions via active transport from the soil.

Give an adaptation of a root hair cell. (1)

They have a large surface area due to root hairs, meaning more water can move in.

Give an adaptation of a root hair cell. (2)

They have a large permanent vacuole which affects the speed of movement from the soil to the cell.

Give an adaptation of a root hair cell. (3)

They have lots of mitochondria to provide energy from respiration for the active transport of mineral ions into the root hair cell.

What are Xylem cells specialised for?

Transporting water and mineral ions up the plant from the roots to the shoots.

Give an adaptation of a xylem cell. (1)

They become strengthened by a substance called lignin. Lignin gives strength and support to the plant.

Give an adaptation of a xylem cell. (2)

They lose their end walls so the xylem forms a continuous, hollow tube so water and mineral ions can pass through.

What are Phloem cells specialised for?

They are specialised to carry the products of photosynthesis (food) to the plant.

Give an adaptation of a phloem cell. (1)

The cell walls of each cell form structures called sieve plates when they break down, allowing the movement of substances from cell to cell.

Give an adaptation of a phloem cell. (2)

Transport of substances in the phloem requires energy. One or more companion cells attached to each sieve tube provide this energy. A sieve tube is completely dependent on its companion cell(s).