biology

• microscopes are used to look at objects that are too small for you to see normally
• a nucleus controls what the cell does
• the cytoplasm is a sort of jelly that fills the cell where most chemical reactions happen
• the cell membrane is a think skin around the cell that holds the cell together and controls what goes in and out
• mitochondria is where the aerobic respiration happens
• a cell wall is a stiff outer layer around the cell membrane that supports the cell
• a vacuole is filled with cell sap containing sugar and salts
• chloroplasts are where photosynthesis happens
• nucleus contains DNA which carries genetic information
• continuous variation is something that can be and value. for example, height or weight-they can be any value within a range
• discontinuous variation is a feature that can only take certain values, either or, no in between. for example, blood type
• photosynthesis is a chemical process that takes place in every green plant
• photosynthesis produces food for the plant in the form of glucose (a carbohydrates)
• Carbon dioxide + Water -> Glucose + Oxygen
• a balanced diet has to have the right amount of the five nutrients below

  • carbohydrates
  • proteins
  • lipids (fats and oils)
  • vitamins
  • minerals
• a balanced diet must also have enough fibre and water
• parts of digestion

  • mouth - food is mixed with saliva containing an enzyme that breaks down carbohydrates
  • gullet - link the mouth to the stomach
  • stomach - food mixes with enzymes that break down proteins. Stomach acid kills harmful bacteria
  • liver - creates liquid called bile that gets squirted into the small intestines that then breaks fats into tiny droplets
  • pancreas - contains glandular tissue that makes enzymes to break down food
  • small intestine - food is absorbed from the small intestine into the blood
  • large intestine - water is absorbed from the food into the blood
• aerobic respiration is respiration using oxygen
• anaerobic respiration is respiration without oxygen
• in aerobic respiration, glucose and oxygen react to produce carbon dioxide and water. This reaction releases lots of energy.
• word equation for aerobic respiration

  glucose + oxygen -> carbon dioxide + water (+energy)
• anaerobic respiration releases less energy than aerobic respiration and takes place during hard exercise
• word equation for anaerobic respiration

  glucose -> lactic acid
• male parts of the flower (stamen) :

  • anther
  • filament
• female parts of the flower :

  • stigma
  • style
  • ovary
• the following are needed for photosynthesis :

  • sunlight
  • carbon dioxide
  • water
  • chlorophyll
• smoking reduces the amount of blood flow and oxygen that can reach the foetus