Advertisements
Advertisements
प्रश्न
A candidate studied the importance of certain factors in photosynthesis. He took a potted plant and kept in the dark for over 24 hours. In the early hours of the next morning, he covered one of the leaves with black paper in the centre only. Then he placed the plant in sunlight for a few hours and tested the leaf which was covered with black paper for starch.
Describe step by step, how the candidate proceeded to test the leaf for the presence of starch?
उत्तर
- The student dipped the leaf in boiling water for a minute to kill the cells.
- Then he boiled the leaf in alcohol/methylated spirit over a water bath to remove chlorophyll. The leaf becomes hard and brittle.
- He then places the leaf in hot water to soften it.
- Next the student spreads the leaf in a dish and pours iodine solution on it. The presence of starch is indicated by a blue-black colour.
- The uncovered portion (exposed to sunlight) turned blue-black colour and the covered portion showed brown colour. The difference in the colours of covered and uncovered part of leaves indicates the importance of sunlight in photosynthesis.
APPEARS IN
संबंधित प्रश्न
Differentiate between the following pairs on the basis of what is indicated in the brackets.
Leaf and Liver [form in which glucose is stored]
The diagram given below represents an experiment to prove the importance of a factor in photosynthesis. Answer the questions that follow : 
Draw a neat, labelled diagram of an experimental steup to show that oxygen is released during photosynthesis
Fill in the blank:
Xanthophyll is ______ coloured pigment.
Name the following:
The organisms that can be called "natural purifiers" of the air.
Identify the false statement and rewrite it correctly by changing the first or last word only.
Green plants are consumers.
The site of light reaction in the cells of a leaf is ______.
What is the importance of photosynthesis in the life of the following:
Green plants
Explain the Term NADPH.
Give technical term:
Name the process which is responsible for the conversion of solar energy to chemical energy that is essential to sustain life on this earth?
Give technical term:
What does ATP abbreviate for?
Choose the Odd One Out
Choose the Odd One Out
Column ‘II’ is a list of items related to ideas in Column ‘I’. Match the term in Column ‘II’ with the suitable idea given in Column ‘I’.
| Column I | Column II | ||
| (i) | Grana | (a) | Decomposers |
| (ii) | Autotrophs | (b) | Light reaction |
| (iii) | By-products of photosynthesis | (c) | Animals |
| (iv) | Photolysis | (d) | Oxygen |
| (v) | Bacteria and fungi | (e) | Stimulated by light |
| (vi) | Chloroplast | (f) | Power |
| (vii) | Oxygen and water | (g) | Raw material |
| (viii) | Sunlight | (h) | Machinery |
| (ix) | CO2 and water | (i) | End products |
| (x) | Glucose (sugar) | (j) | Workrooms |
| (xi) | Cells in the leaf | (k) | By-products. |
Gas exchange takes place in plants using _____.
A plant is kept in a dark room for about 24 hours before conducting any experiment on photosynthesis in order to ______.
