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Photosynthesis in Higher Plants
Why is the colour of a leaf kept in the dark frequently yellow, or pal...

Why is the colour of a leaf kept in the | Class 11 Biology Chapter Photosynthesis in Higher Plants, Photosynthesis in Higher Plants NCERT Solutions

Welcome to the NCERT Solutions for Class 11 Biology - Chapter Photosynthesis in Higher Plants. This page offers a step-by-step solution to the specific question from Exercise 1, Question 6: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 6: Why is the colour of a leaf kept in the dark frequently yellow, or pale green? Which pigment do you think is more stable?

Answer:

Since leaves require light to perform photosynthesis, the colour of a leaf kept in the dark changes from a darker to a lighter shade of green. Sometimes, it also turns yellow. The production of the chlorophyll pigment essential for photosynthesis is directly proportional to the amount of light available. In the absence of light, the production of chlorophyll-a molecules stops and they get broken slowly. This changes the colour of the leaf gradually to light green. During this process, the xanthophyll and carotenoid pigments become predominant, causing the leaf to become yellow. These pigments are more stable as light is not essential for their production. They are always present in plants.

Other Questions of Chapter Photosynthesis in Higher Plants

Q: Look at leaves of the same plant on the shady side and compare it with the leaves on the sunny side. Or, compare the potted plants kept in the sunlight with those in the shade. Which of them has leaves that are darker green? Why?

Q: Give comparison between the following:
(a) C3 and C4 pathways
(b) Cyclic and non-cyclic photophosphorylation
(c) Anatomy of leaf in C3 and C4 plants

Q: RuBisCo is an enzyme that acts both as a carboxylase and oxygenase. Why do you think RuBisCo carries out more carboxylation in C4plants?

Q: Suppose there were plants that had a high concentration of Chlorophyll-b, but lacked chlorophyll-a, would it carry out photosynthesis? Then why do plants have chlorophyll-b and other accessory pigments?

Q: Figure 13.10 shows the effect of light on the rate of photosynthesis. Based on the graph, answer the following questions:
(a) At which point/s (A, B or C) in the curve is light a limiting factor?
(b) What could be the limiting factor/s in region A?
(c) What do C and D represent on the curve?

Q: Even though a very few cells in a C4 plant carry out the biosynthetic Calvin pathway, yet they are highly productive. Can you discuss why?

Q: By looking at a plant externally can you tell whether a plant is C3 or C4? Why and how?

Q: By looking at which internal structure of a plant can you tell whether a plant is C3 or C4? Explain.

Popular questions of class 11 Biology

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Q: What is the difference between direct and indirect development?

Define a taxon. Give some examples of taxa at different hierarchical levels.

Q: Describe the important properties of enzymes.

What are the steps involved in formation of a root nodule?

Q: Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.

Q: How is a key helpful in the identification and classification of an organism?

Q: What is stomatal apparatus? Explain the structure of stomata with a labelled diagram.

Recently Viewed Questions of Class 11 Biology

Name the pathological condition when uncontrolled cell division occurs.

Aquatic animals generally are ammonotelic in nature where as terrestual forms are not. Comment.

Name the cells/tissues in human body which
a. exhibit ameboid movement
b. exhibit ciliary movement

Q: How is the study of plant anatomy useful to us?

How do you distinguish between a skeletal muscle and a cardiac muscle?

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Why earthworm is called the friend of farmer?

Q: Draw the labelled diagram of the following:
(i) Gram seed
(ii) V.S. of maize seed

Which of the following is correct:
(a) Cells of all living organisms have a nucleus.
(b) Both animal and plant cells have a well defined cell wall.
(c) In prokaryotes, there are no membrane bound organelles.
(d) Cells are formed de novo from abiotic materials.

Mitosis results in producing two cells which are similar to each other. What would be the consequence if each of the following irregularities
occur during mitosis?
a. Nuclear membrane fails to disintegrate
b. Duplication of DNA does not occur
c. Centromeres do not divide
d. Cytokinesis does not occur.

Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

Read the question carefully and focus on the core concept being asked.
Reference examples and data from the chapter when answering questions about Photosynthesis in Higher Plants.
Review previous year question papers to get an idea of how such questions may be framed in exams.
Practice answering questions within the time limit to improve your speed and accuracy.
Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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Comments

Sai
Oct 09, 2019

Out standing

Himalayan Tenzin
Jun 10, 2016

Thank you for the valuable information. :)