Page 113 - Biology - XII

PROJECT - 9

Objective
To study the percentage of imbibition in various seeds in various solutions.

Principle/Theory
1. The taking up of water and consequently swelling of substances is called imbibition.
2. This helps in various physiological processes.

3. Some seeds take up as much as 15 times water than its own weight by imbibition.
4. Water is also imbibed by some substances as vapour.
5. This process involves diff usion, capillary action, and surface tension to some extent.

Materials Required
Varieties of dry seeds (gram, pea, bean, maize, rice, wheat), NaCl solutions of diff erent concentrations (5%,
10%, 20%), sucrose solutions (5%, 10%, 20%), beakers, and chemical balance weights

Procedure
1. Take the required dry seeds and weigh them separately. Take 25 g of each seeds.
2. Keep the seeds in separate beakers. (Study one variety of seed at a time.) Put NaCl and sucrose solutions
of various/diff erent concentration in separate beakers.
3. Keep the sets for 24–72 hours.

4. Repeat the process with other seeds. And note your observation by weighing the seeds after they have
imbibed the contents/liquid.

Results
1. The same variety of seeds imbibe diff erent amount of liquids.
2. Some seeds imbibe more liquid in comparison to other seeds.

Observation Table
Percentage of imbibition in various seeds
Weight after imbibing
S. Name of seed Dry weight Inference
No. NaCl solution Sucrose
5% 10% 20% 5% 10% 20%
1. Gram 25 g

2. Pea 25g
3. Maize 25 g
4. – 25g
5. – 25g

Final weight after – Dry weight imbibing a solution
Calculation of percentage of imbibition = × 100
Dry weight

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