Question

write an activity on presence of starch in leaves by aim,procedure, observation,and conclusions​

Answer 1

Materials Required
bunsen burner,
tripod stand,
wire gauze
beaker boiling tube
anti- bumping granules
forceps
test tube holder
white tile
leaf to be tested (hibiscus leaves are excellent)
90% ethanol
iodine/potassium iodide solution

Procedure

The video above shows the steps in Testing a Leaf for the Presence of Starch. The Procedure outlined below is slightly different.

Remove a green leaf from a plant that has been exposed to sunlight for a few hoursHalf-fill a 250cm3 beaker with water. Heat the water until it boils. Keep the water at boiling point.Use the forceps to place the leaf in the boiling water. Boil for 2 minutes.Turn off the Bunsen Burner. (If you are using a heat source without a naked flame - electric water bath or hot plate - this step is unnecessary.)Place the boiled leaf in a boiling tube containing 90% ethanol.Place the boiling tube in hot water and boil for 10 minutes or until the leaf decolourizes.    ( It may be necessary to replace the ethanol)Gently remove the leaf and wash with a fine trickle of cold tap water.Spread the leaf evenly on a white tile.Add a few drops of iodine/potassium iodide solution to the leaf and note any observations.

Observations/Results

The leaf was flaccid (soft) after being boiled in waterThe ethanol changed from colorless to greenThe leaf was brittle after being boiled in ethanolThe leaf become flaccid once more after being rinsed in cold waterAfter iodine solution was added...

Observation

No color change (Iodine Solution remains brown)

Iodine/Potassium Iodide solution changed from brown to blue- black

Hope it help you

Answer 2

hey mate !!

here is the answer

Aim:to prove carbohydrates (or)starch is present in leaf

Apparatus required :1. wide mouthed

beaker with water

2. Test tube

3. Asbestos gauze

4. Tripod stand

5.Bunsen burner

6. methylated spirit

7.Iodine solution

8.petri dish

9. Narrow leaf

Procedure :

Take a wide mouthed beaker with water

2.Add few ml of methylated spirit and place it in beaker with water

3.The beaker with water is kept on asbestos gauze

4.The entire apparatus are arranged on the tripod stand

5.Heat is applied to beaker with water through asbestos gauze with the help of Bunsen burner

6.The test tube with methylated spirit and narrow leaf is boiled

7.After boiling the leaf in methylated spirit, lift out the leaf from the test tube

8.when the leaf is treated with methylated spirit it looses all pigments. so , the leaf turns into pale white colour .

9. take the leaf into petri dish and pour some drops of Iodine solution .Iodine is a reagent it identifies the presence. of starch in the leaf

Observation:

When the leaf is treated with Iodine solution .The pale coloured leaf turns into dark blue or black colour .The dark blue or black colour indicates the presence of starch in the leaf

conclusion :

By this experiment I conclude that starch is present in leaf

hope it helps you