Seed Germination Experiment Observations

Refraction of Light

• When light passes from a less dense medium to a denser medium, it is refracted towards the normal.
• When light passes from a denser medium to a less dense medium, it is refracted away from the normal.
• Refraction does not occur when light strikes the surface at right angles.
• The apparent depth of an object underwater is less than the real depth.

Applications of Reflection and Refraction

• Reflection is applied in:
  • Searchlights
  • Headlamps
  • Magnifying mirrors
• Refraction is applied in lenses of instruments such as:
  • Camera
  • Binoculars
  • Telescope
  • Spectacles
  • Microscope

Composition of Air

• The components of air are:
  • Nitrogen
  • Carbon dioxide
  • Oxygen
  • Water vapour

Food Nutrients

• Carbohydrates:
  • A food type that can be broken down to release energy
  • Also known as starch
• Protein:
  • A food type that contains nitrogen
  • Makes up the structural parts of body cells and tissues
• Lipids:
  • A food type that includes fats and oils
• Minerals salts:
  • Inorganic substances essential in small amounts for good health
• Vitamins:
  • Organic substance essential in small amounts for normal growth and good health

Dietary Needs and Nutritional Deficiency Diseases

• Dietary needs for different persons:
  • Baby: more proteins and mineral salts
  • Pregnant Mother: more proteins, calcium, iron, and vitamins D
• Nutritional deficiency diseases and symptoms:
  • Kwashiorkor
    • Hair loss
    • Swollen stomach
    • Swollen ankles, feet, and hands
    • Enlarged fatty liver
    • Diarrhea
    • Anemia
    • Loss of teeth
    • Loss of skin color
    • Loss of appetite
  • Marasmas
    • Swollen stomach
    • Dry skin
    • Loose skin folds
    • Extreme hunger
    • General tissue and muscle wasting
  • Rickets
  • Scurvy
  • Anemia
  • Depression

Plant Growth and Germination

• When positioning seeds, arrange at a 45⁰ angle so that their radicals (roots) point upwards and their plumules (shoots) point downwards.
• Place in a warm, sunny place and ensure the cotton wool is kept moist at all times.
• Observations and results:
  • Roots of germinating seeds curve away from the top of the beaker and grow downwards.
  • Shoots of germinating seeds curve away from the bottom of the beaker and grow downwards.
• Conclusion:
  • Stems are negatively geotropic (growing upwards).
  • Roots are positively geotropic (growing downwards).

Nutrients Important to Plant Growth

• Major elements:
  • Potassium
  • Nitrogen
  • Phosphorous
• Other nutrients required by plants:
  • Calcium
  • Magnesium
  • Sodium
  • Iron
  • Sulphur.