Test prep

• micropyle: a small hole in the testa that allows water to enter the seed
• hilum: is a scar or mark left by the stalk that attached the seed to the fruit
• testa: (seed coat) - the outer coat that protects the seed from fungi, bacteria, and insects.
• Radicle: (young root) - the part of the seed that develop into the root of the plant
• Plummule: (young shoot) - the part of the seed that will develop into the shoot of the plant.
• Embryo: (young plant) - is the part of the seed that will develop into the new plant
• Cotyledon (seed leaf) - part of the seed that has stored food.
• The stored food is used by the young plant to grow until it becomes green and can make its food by photosynthesis
• The cotyledon helps to protect the plumule from damage during its passage through the soil
• Steps for germination

  1. The seed absorbs water and swells
  2. At the correct temperature, the radicle bursts through the testa
  3. It grows down into the soil until root hairs appear
  4. The embryo grows, using up the food reserves in the cotyledon.
  5. Cotyledons burst out of the testa and above ground, become green, and make food by photosynthesis.
  6. The testa is pushed off and the cotyledons separate, exposing the plumule to sunlight
  7. The first leaves appear, become green, and start making food. The cotyledons fall off.
• Fruits and seeds are scattered by

  1. Wind dispersal
  2. Animal dispersal
  3. Mechanical dispersal