Edexcel IGCSE Geography 復(fù)習(xí)筆記 1.1.1 The Hydrological Cycle Characteristics of the Water Cycle The hydrological cycle is a?closed?system Water is constantly recycled through the system Within the...
Emergent Properties Multicellular organisms are able to undertake functions that unicellular organisms cannot, e.g. move over vast distances and digest large macromolecules Scientists sometimes sum...
Surface Area to Volume Ratio Materials?constantly being?exchanged?across the?plasma membrane The?volume/mass?of cytoplasm (as this is where the reactions take place)For cells to survive, metabolic ...
Functions of Life Unicellular (single-celled) and multicellular (many cells) organisms must carry out the following functions to stay alive: Metabolism - all the enzyme-catalysed reactions occurrin...
Cell Theory Until microscopes became powerful enough to view individual cells, no-one knew for certain what living organisms were made from A scientist called?Robert Hooke?came up with the term "ce...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 8.3.3 Galactic Red-shift Galactic Red-shift The Doppler effect affects all types of waves, including?light Light emitted from stars and galaxies will be at a c...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 8.3.2 Doppler Shift The Doppler Effect Usually, when an object emits waves, the wavefronts spread out?symmetrically If the wave source moves, the waves can bec...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 8.3.1 The Big Bang Theory The Big Bang Theory Around?14 billion years ago,?the Universe began from a?very small region?that was?extremely hot?and?dense Then th...
Edexcel IGCSE Physics 復(fù)習(xí)筆記 8.2.5 Hertzsprung-Russell Diagrams Hertzsprung-Russell Diagrams Stars are classified using the Hertzsprung-Russell (HR) diagram This is a plot of: The?luminosi...
