Search over 10,000 free study notes

Red blood cells are highly adapted to be efficient at absorbing and storing oxygen to carry around the body to be used for aerobic respiration . There are three main adaptations; Biconcave shape - this maxim...

Ionic bonding describes the electrostatic forces of attraction between a metal and a non-metal ion, which are oppositely charged. For example, with NaCl, Na loses an electron to become Na + and Cl gains this...

Depending on the expression how to expand and simplify is different. Commonly for two brackets back to back these are expanded by the FOIL method. Multiply together the two first parts of the brackets, then ...

we need to have a common denominator (bottom number the same) to be able to add or subtract fractionsmultiply first fraction by (x+4) on numerator (top) and denominator (bottom)multiply second fraction by (x...

• acid in stomach kills pathogens in food• skin forms a barrier / produces antimicrobial secretions• hairs in the nose trap (particles which may contain) pathogens• trachea / bronchi has mucus which traps pa...