B2-organisation

• The spongy mesophyll is the middle layer of the leaf and contains lots of air spaces to allow gasses to diffuse in and out of cells
• Guard cells control the opening and closing of the stomata in response to environment conditions to control water loss and gas exchange
• Malignant tumours are cancerous
• Benign tumours are not cancerous
• Malignant tumours spread around the body
• Something that causes cancer is called a carcinogen
• Too much alcohol can lead to liver disease and damage brain cells
• Communicable diseases are contagious, whereas non-communicable diseases or not
• White blood cells defend the body against infection
• Plasma is the liquid that carries everything in blood
• Arteries have thick, muscular walls and carry blood at high-pressure
• Stents, keep coronary arteries open, so oxygenated blood can flow to the heart muscle
• Satins reduce cholesterol in the blood, slowing down the rate of fatty deposit formation
• Red blood cells have a bioconcave shape to increase the surface area for oxygen transport
• Capillaries are one cell thick
• Cells are the basic building blocks that make up all living organisms.
• 4) These specialised cells form tissues, which form organs, which form organ sustems (see below).
• Organs are Organised into Organ Systems
• Enzymes Have Special Shapes So They Can Catalyse Reactions