Name:

Seed Imbibition Activity

Question:

What is the mass change of a seed when it imbibes water prior to germination?

Background:

Imbibition is the adsorbance of water by colloidal materials. Unlike osmosis, no membranes are involved. The surfaces of the colloids attract and hold water with intermolecular forces. These layers of adsorbed water push apart the materials and cause swelling. For example, wood will imbibe water and swell. This effect is used to create a sealed container for water, wine or spirits in wooden barrels. Water imbibed by seeds activate enzymes which begin digesting starches stored in the seed. This is the first steps towards germination of the seed.

Equipment:

  1. 15 dry seeds. Seed type: ________________
  2. (1) 100 ml graduated cylinder (also called a graduate).
  3. (1) balance.
  4. paper towels.
  5. sprouting container (250ml beaker)

Procedure:

  1. Determine the seed mass.
  2. Add 100ml water to the seeds.
  3. After 24 hours determine the volume of water absorbed.

Data Section:

  1. ______________ initial mass of seeds
  2. ______________ amount of water absorbed by seeds
  3. ______________ final mass of seeds.

Analysis:

If counted seeds:

  1. Show calculations for average mass of the dry seeds.
  2. Show calculations for water volume adsorbed per seed.
  3. Show calculations for water mass adsorbed per seed.

If you massed seeds:

  1. Show total mass of the dry seeds.
  2. Show calculations for water volume adsorbed per gram of seeds
  3. Show calculations for water mass adsorbed per gram of seeds.