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प्रश्न
(i) Draw a neat and well-labelled diagram of the Chloroplast.
(ii) List the events taking place in the photo-chemical phase of Photosynthesis.
(iii) If you are planning an experiment to show the effect of light on photosynthesis :
(a) Will you select white light or green light? Justify your answer.
(b) Why would you select a destarched plant?
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उत्तर
(ii) The photochemical phase of photosynthesis is light-dependent. A series of chemical reactions occur is quick succession initiated by light, therefore the phase is called photochemical phase. It takes place in chlorophyll-containing thylakoids of chloroplast.
It occurs in the following steps :
(a) The chlorophyll on exposure to light energy becomes activated by absorbing photons.
(b) This energy is used in splitting the water molecules (photolysis) as below :
H2O → H+ + OH–
(c) OH– ions through a series of steps produce water (H2O) and oxygen (O2). Water may be used inside the plant but O2 released into the atmosphere.
(d) H+ combines with CO2 in dark reaction to produce glucose.
(iii)
(a) I will select white light because photosynthesis is maximum in white light while it is minimum in green light as the green light is reflected by green plants.
(b) I will select the destarched plant so I can demonstrate the synthesis of starch through the iodine test.
संबंधित प्रश्न
Name the following:
The part of chloroplast where the dark reaction of photosynthesis takes place.
Which tissues and cells are mainly concerned with photosynthesis?
The figure given below represents an experiment to demonstrate a particular aspect of photosynthesis. The alphabet ‘A’ represents a certain condition inside the flask.
(i) What is the aim of the experiment?
(ii) Identify the special condition inside the flask.
(iii) Name an alternative chemical that can be used instead of KOH.
(iv) In what manner do the leaves 1 and 2 differ at the end of the starch test?
A well-watered healthy potted plant with variegated leaves was kept in darkness for about 24 hours. It was then set up as shown in the diagram and exposed to light for about 12 hours. At the end of this time, leaf X and leaf Y were tested for starch. Study the diagram and answer the questions that follow:
(i) Why was the plant initially kept in darkness for 24 hours?
(ii) What is the function of the sodium hydroxide solution in the flask?
(iii) Select the correct leaf from the five available choices shown in the diagram as A, B, C, D, and E. Rewrite the correct answer for the filling in the appropriate letter from the questions that follow:
1. After the starch test, leaf X would look like.
2. After the starch test, leaf Y would look like.
Explain the term Carbon cycle.
Give technical term:
Name the structure where photophosphorylation takes place.
State the location:
Stroma
The basic functional unit of solar energy which is absorbed by the pigment chlorophyll is ______.
Given below are groups of terms. The first pair indicates the relationship between the two terms. Complete the second pair accordingly.
Light reaction : Gran um : : Dark reaction : ______
