plant mineral deficiencies

• IV


  minerals present
• DV 


  physical charactersitics of a plant
• CV

  • Volume of mineral solution used – half a test tube will be filled with each
  • Same species of the plant (Mexican Hat plant) used
  • Size of plantlets used – roughly same length plantlet cuttings should be used for each solution
  • Amount of light received – all test tubes placed in test tube rack which is positioned on a sunny window sill
  • Same amount of time growing – all test tubes should be left for approximately one week before examining plantlets
• equipment

  • 5 Mexican Hat plantlets (roughly equal length)
  • Ruler
  • 5 test tubes
  • Test tube rack
  • Solution containing all minerals
  • Solution containing all minerals except magnesium ions
  • Solution containing all minerals except nitrate ions
  • Solution containing all minerals except calcium ions
  • Solution containing no minerals (distilled water)
  • Aluminium foil
• control


  Solution containing all minerals acts as positive control and solution containing no minerals (just distilled water) acts as negative control.
• method

  1. Half fill a test tube with the solution containing all minerals.
  2. Cover the top of the tube with aluminium foil and push down on covering so that there is a well in the centre.
  3. Gently push the roots of Mexican Hat plantlet through the hole so it is in the solution below.
  4. Repeat steps 1 to 3 with the other 4 solutions.
  5. Wrap all tubes in aluminium foil and place them in the test tube rack on a sunny window sill.
  6. Leave plantlets for approximately one week.
  7. Observe characteristics and growth of the plantlets, comparing each solutions’ effects.
• results

  • Solution containing all minerals – full growth and no abnormalities in characteristics.
  • Solution containing all minerals except magnesium ions – leaves should appear yellow. Growth should be stunted.
  • Solution containing all minerals except nitrate ions – yellow leaves and stunted growth.
  • Solution containing all minerals except calcium ions – growth stunted and may even be shorter than before. Plantlet should be soft and lacking support.
  • Solution containing no minerals (distilled water) – no growth should be observed, plant should have died.
• conclusions

  • Magnesium ions are used to synthesise chlorophyll molecules for photosynthesis. Therefore, plant lacks green colour and growth is stunted as energy source becomes less efficient. 
  • nitrate ions to build amino acids and proteins/polypeptide chains. Proteins are largely responsible for growth and repair and so growth is reduced. The yellow colour is a result of a lack of chlorophyll molecules due to a lack of proteins/enzymes being made.
• conclusions continued

  calcium ions are used to strengthen cell walls and for membrane permeability. Reduced support from weaker cell walls causes a ‘floppy’ stem. Reduced metabolic activity due to reduced membrane permeability results in stunted growth.