Fossils provide evidence for Darwin's Natural Selection theory. Most fossils are found
in sedimentary rocks (limestone) or are impressions.
Functional foods have health benefits over their basic nutritional value;
prebiotics, probiotics and plant stanol esters
Prebiotics are substances the body can't digest, they act as food and encourage beneficial bacteria to grow
Probiotics contain live bacteria which produces lactic acid in the gut; products containing these claim to make your
digestive system healthier. There is no evidence
Plant stanol esters are oily substances found in plants; they stop the small intestine absorbing cholesterol, lowering cholesterol levels.
It is used in drinks and yogurts, there is a positive effect
Blood contains: Red blood cells for oxygen; White blood cells for defence against pathogens;
plasma which transport substances in solutions; Platelets for clotting
Red blood cells contain haemeglobin. Haemoglobin+Oxygen =Oxyhaemoglobin
this reverses when oxygen levels are low
white blood cells make antibodies- proteins which bid to pathogens and destroy them.
Other types of white blood cells surround and engulf pathogens
Platelets make a cross-hatch pattern with protein fibres over an open wound
Arteries carry blood away from the heart; it has thick walls so they can withstand pressure
Veins carry blood to the heart; walls are wide so they can carry a lot of blood at a low pressure
Capilaries allow substances to diffuse into the blood; they have very thin walls
Digestion is the breakdown of large insoluble food molecules, into smaller soluble molecules
Enzymes are responsible for digestion.
Amylase breaks down starch into maltose
Proteases breaks down proteins into Amino
Acids Lipases breaks down Fats into Fatty
Acids and Glycerol
Bile emulisifies large fat globules into smaller ones
percentile charts help us monitor growth in children