LAB 4271 BOT

imbibitions

Imbibition is when the water goes inside the seed

imbibition is necessary for germination.

AIM

To demonstrate that water molecules attach to the molecules of colloids during imbibitions .

Water softens the seed coat Therefore Root and Shoot

comes out .

MATERIALS

Test tubes Seeds Filter paper Weighing scale Water

PROCEDURE

1. Take dry seeds.

2. Place them on a filter paper in Petri dish

(A) With water

(B) Without water

3. Weigh the dry seeds-- W1

4. Add them to a test tube

5. Fill it with water.

6. Weigh again after 8-10 hrs—W2

OBSERVATION

The seed increase in size and weight .

INFERENCE

Water moves by imbibition inside the seeds then helps movement of radicle and plumule .

2 -PROCESS OF OSMOSIS

AIM

To demonstrate the principle of Osmosis with the help of a potato osmoscope (living system).

MATERIALS

Fresh potato Concentrated Sucrose or salt

solution Petri dish Water Pin Peeler Cork borer

PROCEDURE Peel the skin of a potato One of its ends is cut to make it flat. At the other end form a cup/hollow cavity with the

help of cork borer. Pour 5% or 10% sugar solution in to the potato cup

up to a particular level. Pierce a pin to mark the initial level. This set up is called potato osmoscope or potato

osmometer. Place the potato osmoscope in a Petri dish

containing water. Leave the experimental set up undisturbed for about

30 minutes. Observe for the change in the level of sugar solution

in the potato cup.

OBSERVATION

You will be able to record an increase in level caused by osmotic movement of water.

You can repeat the experiment by reversing the situation. Take sugar solution in the container and water in the potato cup.

Mark the initial level. At the end of 30 minutes note the final level.

 

INFERENCE

water moves from weaken solution to stronger solution by osmosis , therefore the level rises .

potato work like a semi permeable membrane .

The end