Specialised cells Objectives: To know different types of cells. To be able to relate structure to function of cells.

Absorbs light energy for photosynthesis Packed with chloroplasts. Regular shaped, closely packed cells form a continuous layer for efficient absorption of sunlight.

Absorbs water and mineral ions from the soil Long 'finger-like' process with very thin wall, which gives a large surface area.

Fertilises an egg cell - female gamete The head contains genetic information and an enzyme to help penetrate the egg cell membrane. The middle section is packed with mitochondria for energy. The tail moves the sperm to the egg.

Contain haemoglobin to carry oxygen to the cells. Thin outer membrane to let oxygen diffuse through easily. Shape increases the surface area to allow more oxygen to be absorbed efficiently. No nucleus, so the whole cell is full of haemoglobin.

Fat cells Human cone cells Root hair cells Sperm cells Have little cytoplasm, making space for the fat store. Outer segment filled with visual pigment which chemically changes in coloured light, reversible reaction. Root hair to increase surface area for osmosis. Long tails with muscle- like proteins. Use little energy so need fewer mitochondria. Many mitochondria needed for the chemical changes of the visual pigment. Large permanent vacuole, affecting the movement of water from the soil across the root hair cell. Many mitochondria needed for swimming action. Expandable, up to 1000 times original size. Electrical impulse triggered by light effects on visual pigment crosses the synapse to optic nerve. Positioned close to the xylem tissue that carries water up to the rest of the plant. Acrosome which stores digestive enzymes for breaking down the outer layers of the egg Large nucleus containing the genetic information to be passed on.