SPECIALISED CELLS

to fertilise the egg

-HEAD is streamlined to enable faster movement -ACROSOME has enzymes to penetrate the lining of the egg • FLAGELLUM which helps it to swim -NUCLEUS contains half of the genetic material (only 23 chromosomes) • MIDDLE SECTION contains lots of mitochondria to release energy to fuel the flagellum

to carry electrical impulses through the brain or body

AXON - a long extension from the main cell body DENDRITES - branches to connect to many other cells MYELIN SHEATH - a layer of fatty insulation around the axon to ensure electrical impulses can be carried for long distances

contract and relax to enable movement inside the body

CONNECTED TOGETHER - so they can exert more force for movement LOTS OF MITOCHONDRIA - to release energy for muscle contractions FILAMENT BUNDLES - slide over one another to become shorter and contract

to transport oxygen from the lungs to respiring cells and carry carbon dioxide back to the lungs.

ADAPTATIONS: -their cytoplasm does not have a NUCLEUS so they can carry more haemoglobin (note: 0 chromosomes) -Red blood cells contain HAEMOGLOBIN, which binds to oxygen to form oxyhaemoglobin, allowing oxygen to be transported efficiently • they are VERY SMALL and FLEXIBLE allowing transport through small capillaries -they have a biconcave disc shape which gives them a LARGE SURFACE AREA :VOLUME RATIO for absorbing as much oxygen as possible from the lungs

to protect the body from disease and infection

TALL AND NARROW- so many cells can make up the lining of the organ (HAIR-LIKE) CILIA- to move mucus and trapped particles along the airways

to absorb water and mineral ions from the soil

LONG EXTENSION- provide a large SA available for the absorption of water and mineral ions THIN CELL WALLS: outer epidermis is one cell thick , this provides a short diffusion distance , increasing the rate of absorption NO CHLOROPLAST -would take up unnecessary space as isn’t exposed to sunlight underground for photosynthesis removed: - SEMI-PERMEABLE CELL MEMBRANE- allows water and mineral ions to pass into the cell

transport water and minerals up the plant and help support the plant.

LIGNIN- a waterproof substance that strengthens the cell NOT LIVING- hollow so water flows through easily . NO CELL WALL OR MEMBRANE AT THE END - lets water and minerals flow freely from one cell to the next. ( cells are not living which means they don’t have a cytoplasm or nucleus , this forms a hollow tube which allows water to flow through it easily)

to transport dissolved sugars made in the leaves

SIEVE TUBE PLATE - has pores to allow cell sap to flow CELLS ARE : long and joined end to end so sugar can flow continuously COMPANION CELLS: which have lots of mitochondria to release energy for transport