Question

Answer the following questions
1.why are leaves suitable for photosynthesis?
2.how will you test for the presence of starch in a leaf? ​

Answer 1

1.As they have chlorophyll.

Answer 2

Question 1: Why are leaves suitable for photosynthesis?

Answer 1:

▶ Leaves are suitable for photosynthesis since, they contain a green pigment known as chlorophyll in them.

▶ Chlorophyll prepares food for the plant by absorbing carbon-dioxide, sunlight and water with the help of chloroplasts/plastids.

Question 2: How will you test for the presence of starch in a leaf? ​

Answer 2:

▶ There is an experiment to test the presence of starch in a leaf

▶ Experiment:

Step 1️⃣: Take a potted plant with variegated leaves – for example, money plant  or crotons.

Step 2️⃣: Keep the plant in a dark room for three days so that all the starch

gets used up.

Step 3️⃣: Now keep the plant in sunlight for about six hours.

Step 4️⃣: Pluck a leaf from the plant. Mark the green areas in it and trace them  on a sheet of paper.

Step 5️⃣: Dip the leaf in boiling water for a few minutes.  Then, immerse it in a beaker containing alcohol.

Step 6️⃣: Carefully place the above beaker in a water-bath and heat till the

alcohol begins to boil.  

Step 7️⃣: Now dip the leaf in a dilute solution of iodine for a few minutes.

Step 8️⃣: Take out the leaf and rinse off the iodine solution.

▶ Note down the observations after performing Step 6️⃣ and Step 8️⃣.

▶In this way, we can test the presence of starch in a leaf.