Plant Mineral Requirement (any two)

• Calcium: for the middle lamella that ‘glues’ neighbouring plant cell walls.
• Magnesium: for the production of chlorophyll so vital for photosynthesis.

Animal Mineral Requirement (any two)

• Calcium: formation of teeth and bones.
• Iron: formation of haemoglobin so vital for oxygen transport in our blood.

General Role of Minerals in Living Organisms

• Construction of Hard Parts: calcium for teeth and bone; nitrogen for chitin in the cell walls of fungi.
• Formation of Soft Tissue: nitrogen and sulphur in the protein of muscle tissue.
• Maintain Correct Fluid Concentration: sodium chloride role in blood plasma concentration.

Water: H₂O

Importance of Water for Organisms

• Fluid Component: 90% of cell cytoplasm, 92% of blood plasma, 97% of tissue fluid and lymph.
• Multipurpose Solvent: medium for metabolism and transport.
• Take Part in Metabolic Reactions
• Photosynthesis: water is a raw material in the light stage.
• Respiration: aerobic respiration produces water.
• Anabolism: water in produced when the subunits of macromolecules link together.
• Catabolism: water is used to break the bonds that hold together the subunits of macromolecules.
• Movement of Materials through Cell Membranes: diffusion, osmosis and active transport.
• Control Cell Shape
• Immature plant cell enlarge to mature size and shape as a result of their absorption of water by osmosis.
• Opening and closing of the stoma by change in shape of the guard cells by change in their turgor.
• Turgor plays an important role in the support of soft plant tissue.
• Good Absorber of Heat Energy
• A lot of heat energy has to be absorbed to bring about an increase in temperature or vaporisation.
• Water as a medium is a temperature-stable which is so important for homeostasis.
• Vaporisation of water is an excellent cooling mechanism.

Mandatory Food Tests

Starch

• Yellow-brown iodine solution is placed on the food sample.
• A blue-black colour indicates that starch is present.
• A yellow-brown colour indicates that starch is not present.

Reducing Sugar

E.g., glucose, fructose, maltose, lactose. (Sucrose is a non-reducing sugar).

• Add an equal volume of blue Benedict’s Reagent to the food solution.
• Heat but do not boil.
• A brick-red colour indicates that reducing sugar is present.
• A blue colour indicates that reducing sugar is not present.
• Control: water – blue colour result.

Lipid

• Rub the food onto brown paper.
• A translucent stain that does not ‘dry out’ indicates fat is present.
• Control: water – stain dries out and the brown paper remains opaque.

Protein

• Biuret Test: Add sodium hydroxide solution to the food solution.
• Then add a few drops of blue copper sulphate solution.
• Shake the contents vigorously.
• A purple-violet colour indicates protein is present.

Ecological Fieldwork: Principles and Practices

Grassland Habitat

Description of Habitat: General Map and/or Photographs taken at different seasons.

Climate: Cold Temperate Oceanic

Дата добавления: 2015-11-14