Careers360 Logo
NCERT Exemplar Class 11 Biology Solutions Chapter 13 Photosynthesis in Higher Plants

NCERT Exemplar Class 11 Biology Solutions Chapter 13 Photosynthesis in Higher Plants

Edited By Priyanka kumari | Updated on Aug 19, 2022 03:40 PM IST

NCERT Exemplar Class 11 Biology solutions chapter 13 - As we already know that plants make their own food using a process called photosynthesis which is a chemical process. In this process, plants use sunlight to convert the glucose from carbon dioxide and water. NCERT Exemplar Class 11 Biology chapter 13 solutions explains this process of photosynthesis in detail along with its different phases. NCERT exemplar Class 11 Biology solutions chapter 13 is a quality study material prepared by experts for the best learning experience. NCERT Exemplar Class 11 Biology chapter 13 solutions PDF Download function to be available. But till then, students can use webpage to PDF tools available online.

NCERT Solution for Class 11 Biology 13 Photosynthesis in Higher Plants:

Multiple Choice Questions:

Question:1

Which metal ion is a constituent of chlorophyll?
a. Copper
b. Magnesium
c. Iron
d. Zinc

Answer:

The answer is the option b. Magnesium
Explanation - The structure of chlorophyll pigment has a chlorine ring at the centre of which a magnesium ion is placed.

Question:2

Which pigment acts directly to convert light energy to chemical energy?
a. Carotenoid
b. Chlorophyll B
c. Chlorophyll A
d. Xanthophyll

Answer:

The answer is the option c. Chlorophyll A
Explanation – The maximum absorption of light is carried out chlorophyll-a pigment. Therefore, it directly converts light energy into chemical energy at a fast rate.

Question:3

Which range of wavelength (in nm) is called photosynthetically active radiation (PAR)?
a. 760 -10,000
b. 400 -700
c. 390 -430
d. 100 -390

Answer:

The answer is the option b. 400 -700

Question:4

Which light range is least effective in photosynthesis?
a. Red
b. Blue
c. Green
d. Violet

Answer:

The answer is the option c. Green
Explanation - The green light range of the spectrum is least effective in photosynthesis. This is because chlorophyll of leaves is green in colour. Due to the green colour, the green wavelength of light is reflected back and does not get absorbed.

Question:5

Chemosynthetic bacteria obtain energy from
a. Organic substances
b. Inorganic chemical
c. Sun
d. Infrared rays

Answer:

The answer is option b. Inorganic chemical
Explanation - For making organic chemicals, chemosynthetic bacteria utilise inorganic chemicals.

Question:6

Energy required for ATP synthesis in PS II comes from
a. Electron gradient
b. Reduction of glucose
c. Oxidation of glucose
d. Proton gradient

Answer:

The answer is the option d.
Proton Gradient

Question:7

During light reaction in photosynthesis the following are formed
a. ATP, hydrogen donor and O 2
b. ATP and sugar
c. ATP, hydrogen and O 2 donor
d. Hydrogen, O 2 and sugar

Answer:

The answer is the option c. ATP, Hydrogen and O 2 donor Explanation - During light reaction, water molecules split and release hydrogen and oxygen donor.

Question:8

Dark reaction in photosynthesis is called so because
a. It does not depend on light energy
b. It cannot occur during day light
c. It occurs during day light
d. It can occur in dark also

Answer:

The answer is option a. It does not depend on light energy
Explanation - Light reaction occurs due to the presence of light when the splitting of water molecules can take place. This results in the formation of ATP. The entire reaction is termed as a light reaction. However, further steps do not depend on the presence of light, and hence the process is termed as a dark reaction. This does not indicate that the process occurs in the dark and not during daytime.

Question:9

PEP is primary CO2 acceptor in
a. C3 plants
b. C4 plants
c. C2 plants
d. Both C3 and C4 plants

Answer:

The answer is the option b. C4 plants
Explanation - PEP is found in mesophyll cells. It is the primary carbon dioxide acceptor in C4 plants

Question:10

Splitting of water is associated with
a. Lumen of thylakoid
b. Photosystem I
c. Both photosystem I and II
d. Inner surface of thylakoid membrane

Answer:

The answer is the option d. Inner surface of thylakoid membrane

Question:11

The correct sequence of flow of electron in the light reaction is
a. PSI, ferredoxin, PSII
b. PSI, plastoquinone, cytochromes, PS II, ferredoxin
c. PS II, plastoquinone, cytochromes, PS I, ferredoxin
d. PS I, plastoquinone, cytochromes, PS I, ferredoxin

Answer:

The answer is the option c. PS II, plastoquinone, cytochromes, PS I, ferredoxin

Question:12

The enzyme that is found in a C3 plant is
a. ATP synthase
b. NADP reductase
c. PEP carboxylase
d. RuBP carboxylase

Answer:

c. PEP carboxylase
Explanation - PEP carboxylase and PEP are not found in C 3 plants.

Question:13

The reaction that is responsible for the primary fixation of CO2 is catalysed by
a. PGA synthase
b. RuBP carboxylase and PEP carboxylase
c. RuBP carboxylase
d. PEP carboxylase

Answer:

b. RuBP carboxylase and PEP carboxylase
Explanation - PEP carboxylase in C4 plants and RuBP carboxylase in C3 plants

Question:14

When CO2 is added to PEP, the first stable product synthesised is
a. Oxaloacetate
b. Pyruvate
c. Glyceraldehyde -3 -phosphate
d. Phosphoglycerate

Answer:

The answer is the option a. Oxaloacetate

Very Short Answer Type Questions:

Question:1

Examine the figure



a. Is this structure present in animal cells or plant cells?
b. Can these be passed on to the progeny? How?
c. Name the metabolic processes taking place I the places marked (1) and (2).

Answer:

a. The structure is only found in plant cells
b. Yes, these can be passed on to the progeny because chloroplast possesses an ability to self -replicate.
c. i) dark reaction occurs
ii) it is the site for chloroplast replication

Question:2

2H _2 O \rightarrow 2H ^{+} + O _2 + 4e^ -
Based on the above equation, answer the following question:
a. Where does this reaction take place in plants?
b. What is the significance of this reaction?

Answer:

a. The above reaction indicates the decomposition of water molecules. This process occurs in PS II. PS II is located at the inner surface of the thylakoid membrane.

b. The reaction signifies that water molecules release electrons for maintaining the electron transport chain. This chain is essential for carrying out the further steps in the photosynthesis process.

Question:3

Cyanobacteria and some other photosynthesis bacteria don’t have chloroplasts. How do they conduct photosynthesis?

Answer:

Chloroplasts are absent in cyanobacteria and similar organism. In these organisms, photosynthesis occurs at the folds of their inner membrane. The presence of bluish pigment phycocyanin captures solar energy for carrying out the process of photosynthesis.

Question:4

A. Breakdown of proton gradient leads to release of ___________

B. NADP reductase enzyme is located on _______

Answer:

A. ATP molecules
B. The outer side of the thylakoid membrane

Question:5

Can girdling experiments be done in monocots? If yes, How? If no, why not?

Answer:

it is not possible to do the girdling experiment in monocots. This is mainly because vascular bundles are scattered all over the stem width of the monocots. Hence, a specific band of phloem can be reached for carrying out the experiment effectively.

Question:6

3CO _2 +9ATP +6NADPH + Water\rightarrow glyceraldehyde 3 -phosphate + 9 ADP + 6 NADP ^+ + 8 Pi
Analyse the above reaction and answer the following question
a. How many molecules of ATP & NADPH are required to fix one molecule of CO2 ?
b. Where in the chloroplast does this process occur?

Answer:

a. 2 molecules of NADPH are required for the reduction process of carbon dioxide, whereas and 3 molecules of ATP are required to carry out the process of phosphorylation. These, in turn, will fix one molecule of carbon dioxide.

b. The process occurs in the stroma.

Question:7

Does moonlight support photosynthesis? Find out.

Answer:

The light energy from the moonlight is not enough to excite the molecules of chlorophyll. Therefore, it is not possible to carry out the process of photosynthesis in the presence of moonlight.

Question:8

Some of these terms/ chemicals are associated with the C4 cycle Explain
a. Hatch slack pathway
b. Calvin cycle
c. PEP carboxylase
d. Bundle sheath cells

Answer:

a. The hatch and slack pathway indicate the process of synthesis of glucose in the C4 plants. It was first discovered in the year 1977 by two scientists named M D Hatch and C R Slack.

b. During photosynthesis, the splitting of water molecules results in the formation of carbohydrates. This cycle of carbohydrate formation is termed as Calvin cycle. It was discovered by Melvin Calvin.

c. PEP carboxylase is an enzyme responsible for fixing carbon and forming oxaloacetate. It is mainly present in C4 plants.

d. Bundle sheath cells are special sclerenchyma cells located around the vascular bundles in the veins of C 4 plants.

Question:9

Where is NADP reductase enzyme located in the chloroplast? What is the role of this enzyme in proton gradient development?

Answer:

The NADP reductase enzyme is found in the outer region of the thylakoid membrane. It helps in the breakdown of the proton gradient and results in the release of energy in the form of NADPH.

Question:10

ATPase enzyme consists of two parts. What are those parts? What are those parts? How are they arranged in the thylakoid membrane? Conformational change occurs in which part of the enzyme?

Answer:

The two parts of the ATPase enzyme are called the F0 head and F1 head. The F0 head is located towards the inner region of the thylakoid whereas the F1 head is located towards the outer region of the thylakoid. The conformational changes take place in the F1 segment of the ATPase enzyme.

Question:11

Which products formed during the light reaction of photosynthesis are used to drive the dark reaction?

Answer:

The products formed during the light reaction of photosynthesis used for driving the dark reaction further are NADPH and ATP.

Question:12

What is the basis for designating C3 and C4 pathways of photosynthesis?

Answer:

In the C3 pathway, carbon is fixed into 3-PGA, which is a 3- carbon compound. However, in the C4 pathway, carbon is fixed into oxaloacetic acid, which is a 4-carbon compound. Hence, the C3 and C4 pathways are designated on the basis of the carbon compound number in the end product.

Short Answer Type Questions:

Question:1

Succulents are known to keep their stomata closed during the day to check transpiration. How do they meet their photosynthetic CO2 requirements?

Answer:

Succulents plants keep their stomata closed during the daytime. However, this also restricts the entry of carbon dioxide. In order to ensure the presence of carbon dioxide within the plant body, the succulent plants have adopted a special method for carbon dioxide supply during the daytime.

The method allows the plants to fix carbon dioxide in the form of malic acid during the night times.

Question:2

Chlorophyll ‘a’ is the primary pigment for light reaction. What are the accessory pigments? What is their role in photosynthesis?

Answer:

Accessory pigments help chlorophyll in trapping the light energy. Accessory pigments present in plants are chlorophyll b- xanthophylls and carotenoids. The accessory pigments help in harvesting the trapped solar energy and pass it further to chlorophyll-a, therefore, can carry out the supporting process during light harvesting.

Question:3

Does reaction of photosynthesis call, as ‘dark reaction’ need light? Explain.

Answer:

During the dark reaction, synthesis of carbohydrate occurs.The dark reaction does not directly depend on the presence of light, and therefore, the process is known as the dark reaction. The dark reaction occurs during daytime as well and does not require complete darkness. So, dark reaction indirectly requires solar energy but can continue without it as well.

Question:4

How are photosynthesis and respiration related to each other?

Answer:

During respiration, oxidation of carbohydrate occurs to release energy. These carbohydrates are prepared by the process of photosynthesis. Therefore, it is evident that both processes are interlinked. Moreover, respiration requires oxygen which is released as a by-product of photosynthesis. Similarly, the carbon dioxide absorbed during respiration is essentially required for the process of
photosynthesis.

Question:5

If a green plant is kept in dark with proper ventilation, can this plant carry out photosynthesis? Can anything be given as supplement to maintain its growth or survival?

Answer:

If a plant is kept under dark light with proper ventilation requirement, it will continuously get carbon dioxide. However, due to the absence of sunlight, photosynthesis will not be able to occur. Water and nutrients must be supplied properly to the plant; otherwise, it will die out.

Question:6

Photosynthesis organisms occur at different depths in the ocean. Do they receive qualitatively and quantitatively the same light? How do they adapt to carry out photosynthesis under these conditions?

Answer:

Light saturation takes place at 10 per cent level of complete sunlight. Therefore, light energy is rarely considered to be a limiting factor during the process of photosynthesis. Photosynthetic plants in the deep ocean are supplied with enough light energy to carry the process of photosynthesis effectively. Furthermore, the plants showcase a variation of the constituent pigments. These pigments ensure that photosynthesis occurs at different light presence.

Question:7

In tropical rain forests, the canopy is thick and shorter plants growing below it, receive filtered light. How are they able to carry out photosynthesis?

Answer:

The photosynthesis process occurring in the thick canopy in the forest can be slowed down due to the presence of less amount of light. However, the process of photosynthesis will be entirely shut down but will occur effectively during the daytime.

Question:8

What conditions enable RuBisCO to function as on oxygenase? Explain the ensuing process.

Answer:

RuBisCO possesses an affinity for carbon dioxide and oxygen. In the presence of high carbon dioxide concentration, the enzyme would effectively result in the formation of carboxylase. But in the presence of a high concentration of oxygen, the enzyme would react and form oxygenase.

Question:9

Why does the rate of photosynthesis decrease at higher temperature?

Answer:

Under high-temperature conditions, the rate of photosynthesis decreases. This is because photosynthesis is an enzyme-mediated reaction. These enzymes work effectively under optimum temperature conditions. When the temperature range increases the optimum value, the process gets affected.

Question:10

Explain how the light reaction of photosynthesis, ATP synthesis is a chemiosmotic phenomenon.

Answer:

ATP is a chemiosmotic process. This indicates that the movement of ions occurs across a semi-permeable membrane and down an electronic gradient. During the light reaction of photosynthesis, ATP is synthesised. During ATP synthesis, the movement of ions occurs across the semi-permeable membrane of the thylakoid. The proton pump pushes the ions with the help of a proton gradient. This further synthesis the ATP molecules. Since this process is a chemical mediated phenomenon, the ATP synthesis is often termed as a chemiosmotic phenomenon.



Question:11

Find out how Melvin Calvin worked out the complete biosynthetic pathway for synthesis of sugar.

Answer:

Melvin Calvin discovered the Calvin cycle and claimed the processes occur in a cyclic manner. The following steps were used for the experiment.
- For the experiment, carbon dioxide atoms were indicated by the symbol of C14 and were effectively supplied to the plant.
- The pathway of C14 was observed wisely and different conditions were analysed.
- After the completion of the experiment, the plant taken was killed,and the compound manufactured inside was taken for further analysis.
- Based on the data extracted from the analysis of the living and dead plants, the Calvin pathway was discovered.

Question:12

Six turns of Calvin cycle are required to generate one mole of glucose. Explain.

Answer:

For the reduction of one carbon dioxide molecule, two molecules of NADPH and 2 molecules of ATP are required. Moreover, 6 molecules of carbon dioxide are required to make one molecule of glucose. Therefore, 6 turns of the Calvin cycle are necessary for making one mole of glucose.

Question:14

In what kind of plants do you come across ‘Kranz’ anatomy? To which conditions are those plants better adapted? How are these plants better adapted than the plants, which lack this anatomy?

Answer:

Kranz anatomy is usually present in C 4 plants like maise, sugarcane, etc. C 4 plants possess the power to tolerate high- temperature ranges and high light intensities. C 4 plants are designed to effectively live in the presence of limited nitrogen and carbon dioxide sources. These factors help in the manufacturing of glucose easily. Therefore, C 3 plants produce less biomass as compared to C 4 plants.

Question:15

A process is occurring throughout the day, in ’X’ organism. Cells are participating in this process. During this process ATP, CO2 and water are evolved. It is not a light dependent process.
a. Name the process
b. Is it a catabolic or an anabolic process?
c. What could be the raw material of this process?

Answer:

a. The name of the process is respiration
b. It is a catabolic process
c. The raw material of the process is a carbohydrate

Question:16

Tomatoes, carrots and chillies are red in colour due to the presence of one pigment. Name the pigment. Is it a photosynthetic pigment?

Answer:

Tomatoes, Chillies and Carrots are red in colour due to the presence of a pigment called Lycopene. Lycopene is not a photosynthetic pigment and is found in the chromoplast plastid.

Question:17

Why do we believe chloroplast and mitochondria to be semi- autonomous organelle?

Answer:

chloroplast and mitochondria are semi-autonomous organelles because they possess an extra genomic DNA which helps them in the replication process. Therefore, they are termed as semi- autonomous organelles.

Question:18

Observe the diagram and answer the following.



a. Which group of plants exhibit these two types of cells?
b. What is the first product of the C 4 cycle?
c. Which enzyme is there in bundle sheath cells and mesophyll cells?

Answer:

a. Bundle sheath cells and mesophyll cells are found in monocot plants
b. Oxaloacetic acid
c. PEP carboxylase or PEPcase.

Question:19

A cyclic process is occurring in a C 3 plant, which is light-dependent and needs O2. This process does not produce energy; rather, it consumes energy.
a. Can you name the given process?
b. Is it essential for survival?
c. What are the end products of this process?
d. Where does it occur?

Answer:

a. The name of the process is called photorespiration
b. No, it is not vital for survival
c. The end product of the process is hydrogen peroxide
d. It occurs in chloroplast, mitochondria, and peroxisomes.

Question:20

Suppose euphorbia and maise are grown in the tropical areas.

a. Which one of them do you think will be able to survive under such conditions?
b. Which one of them is more efficient in terms of photosynthetic activity?
c. What difference do you think are there in their leaf anatomy?

Answer:

a. Euphorbia is a CAM plant. Therefore, it will be able to survive under such conditions.
b. Maise will be more efficient in the photosynthesis activity since it is a C4 plant.
c. Kranz leaf anatomy is found in maise plants. In contrast, it is absent in euphorbia.

NCERT Exemplar Class 11 Biology Solutions Chapter 13 Photosynthesis in Higher Plants - Main Subtopics:

Question:1

Is it correct to say that photosynthesis occurs only in leaves of a plant? Besides leaves, what are the other parts that may be capable of carrying out photosynthesis? Justify.

Answer:

Photosynthesis occurs in green parts of the plants which include parts other than the leaves as well. Therefore, it is incorrect to say that photosynthesis occurs in the leaves only. Most of the other parts of the plants are effective enough to carry out the process of photosynthesis. Some of the examples are listed below.
i) In plants, sepals are green in colour. Therefore, they also carry out photosynthesis.
ii) The roots of Tinospora and Trapa possess chlorophyll and can carry out the process of photosynthesis.
iii) In the case of opuntia, the leaves are modified into thorns resulting in low transpiration rate. Moreover, the stems are also modified into green structures. Therefore, photosynthesis can occur in these stems.

Question:2

The entire process of photosynthesis consists of a number of reactions.Where in the cell does each of these take place?
a. Synthesis of ATP and NADPH_____
b. Photolysis of water_______
c. Fixation of CO2 _______
d. Synthesis of sugar molecule________
e. Synthesis of starch________

Answer:

a. Outer region of the thylakoid membrane
b. Inner region of the thylakoid membrane
c. Stroma region of chloroplast
d. Chloroplast of plants
e. Cytoplasm of plant cells

Question:3

What property of the pigment is responsible for its ability to initiate the process of photosynthesis? Why is the rate of photosynthesis higher in the red and blue regions of the spectrum of light?

Answer:

pigments present in plants help in absorbing light at a specific wavelength. This indicates that different plant pigments can be absorbed by different lights of the spectrum. After getting excited, a pigment provides light energy which can be utilised to initiate the process of photosynthesis.


The plants' cells are enriched in a green coloured pigment called chlorophyll. Chlorophyll indicates an optimum efficiency range between the red and blue wavelength ranges.
Chlorophyll-a is mainly responsible for keeping the photosynthesis at an optimum level of blue and red -light wavelengths.

Question:4

What can we conclude from the statement that the action and absorption spectrum of photosynthesis overlap? At which wavelength do they show peaks?

Answer:

In order to justify the above statement, it is vital to analyse the below graphs.

The first graph indicates the rate of photosynthesis measured with the help ofoxygen released in the process. The second graph indicates the absorption values of various wavelengths of light by the chlorophyll pigment a. Both the graphs have a peaking value at more than 400 nm of a wavelength which becomes equivalent to the wavelength of blue colour. Post that range; the graphs indicate a trough. Later, the values increase again and lie between the range of 600 and 700 nm of wavelength. This value is equivalent to the wavelength of red colour. This indicates the action and absorption spectrums overlap with each other. The black line indicates the action process of photosynthesis. The blue line indicates the absorption process with 430 -470 nm and 660 -670 nm wavelength values.

Question:5

Under what conditions are C4 plants superior to C3 ?

Answer:

C4 plants are considered to be superior to C3 plants. This is because of the following reasons.

- C4 plats indicate a high optimum temperature value, whereas C3 plants indicate the lesser value of optimum temperature ranges. As a result, photosynthesis in C4 plants can take place in the presence of high-temperature ranges, whereas C3 plants cannot initiate photosynthesis under such conditions.

- At low carbon dioxide ranges, C4 plants can carry out the process of photosynthesis effectively. At the same time, C3 plants fail to do so. This is because the presence of carbon dioxide is a limiting factor in the case of C3 plants.

- High oxygen levels in the environment affect C3 plants because Kranz anatomy is absent. This is not in case of C4 plants. Kranz
anatomy in C4 plants ensures that photorespiration do not occur.

Question:6

In the figure given below, the black line(upper) indicates action spectrum for photosynthesis and the lighter line(below) indicates the absorption spectrum of chlorophyll a, answer the followings:



a. What does the action spectrum indicate? How can we plat an action spectrum? Explain with an example.
b. How can we derive an absorption spectrum for any substance?
c. If chlorophyll-a is responsible for the light reaction of photosynthesis, why do the action spectrum and absorption spectrum not overlap?

Answer:

a. The action spectrum indicates the process and rate of photosynthesis.This rate is calculated by the amount of oxygen released. An actionspectrum can be drawn by keeping the amount of released oxygen on the y-axis and the wavelength of light on the x-axis. The pigments which absorb the different wavelength of light will be indicated the graph. The above graph, however, shows hlorophyll.

b. An absorption spectrum for any substance can be drawn by plotting the absorption of various light wavelength by different pigments like chlorophyll a or chlorophyll b.

c. The action spectrum does not overlap because of the presence of other pigments. These other pigments are called the accessory pigments and help in harvesting solar energy. As a result, the spectrum is always at a high level as compared to the absorption spectrum.

Photosynthesis in Higher Plants Excercise: 1.4

Question:7

What are the important events and end products of the light reaction?

Answer:

The important events and end products of the light reaction are listed below.

  • Light absorption - it is carried out with the help of light-harvesting complex or the LHC. The photosystem is composed of everal pigments which form the antennae. The pigments help in absorbing light of various wavelengths. The chlorophyll a molecule works as the centre at which the reaction occurs.
  • Water splitting - the solar energy absorbed by the plant helps in splitting the water molecules to release oxygen and hydrogen ion. The electrons released during this step is used by the NADP ion to form NADPH.
  • Oxygen release - the oxygen which is results from the water-splitting process moves out through the stomatal opening.
  • Formation of ATP and NADPH - the light reaction results in the formation of two high energy intermediate compounds, ATP and NADPH.

Question:8

In the diagram shown below label A, B, C. What type of phosphorylation is possible in this?

Answer:

The process of cyclic phosphorylation is being depicted in this diagram.


Question:9

Why is the RuBisCo enzyme more appropriately called RUBP Carboxylase -Oxygenase, and what important role does it play in photosynthesis?

Answer:

The RuBisCo enzyme possesses an affinity for oxygen as well as carbon dioxide. However, the binding reaction depends on the level of concentration of oxygen and carbon dioxide. Due to this fact, it can act like a carboxylase as well as an oxygenase. Therefore, it is often called RUBP Carboxylase-Oxygenase compound.

In C3 plants, RuBisCo enzyme helps in binding with the carbon dioxide molecule and results in the production of 3PGA. Some of the enzyme molecules also bind with oxygen and results in the production of phosphoglycerate and phosphoglycerate. These are formed during the process of photorespiration. This process, in turn, decreases the carbon fixation in C3 plants.

RuBisCo enzyme plays an essential role in C4 plants as well. Due to the increased concentration of carbon dioxide, the production of oxaloacetic acid is catalysed with the help of this enzyme. Carbon fixation becomes more efficient since the process of photorespiration is prevented.

Question:10

What special autonomous features are displayed by leaves of C4 plants? How do they provide an advantage over the structure of C3 plants?

Answer:

The C4 plants showcase special anatomy commonly known as the Kranz anatomy. The vascular bundles in the leaves are surrounded by a large sheath of cells. Several layers of these cells get multiplied with the help of chloroplast. The thick walls of the bundle sheath cell do not have intercellular spaces. These cell layers provide a greater advantage to the C4 plants and therefore helps in accelerating the concentration of carbon dioxide. The binding of enzyme RuBisCo depends on the competitive concentration of oxygen and carbon dioxide. Therefore, high levels of CO2 help in resulting in the formation of carboxylase. This also results in carbon fixation. The entire scenario results in high levels of biomass as compared to the C3 plants.

Question:11

Name the two important enzymes of C3 and C4 pathway, respectively? What important role do they play in fixing CO2 ?

Answer:

The two vital enzymes of C3 and C4 pathway are RuBisCo and PEPcase, respectively. RuBisCo acts as a carbon dioxide acceptor in C3 plants, whereas PEPcase performs the same function in C4 plants. RuBisCo is known as RUBP Carboxylase Oxygenase. The enzyme possesses a better affinity towards CO2 than O2 .
Although, during the process of photorespiration, the enzyme binds with oxygen. The resultant products are of no value to the plat and result in low carbon fixation in C 3 plants.
PEPcase helps in accepting CO 2 molecules in the C 4 plants. It combines with carbon dioxide to result in the formation of a 4-carbon compound called OAA or oxaloacetic acid. This is further converted into carbon dioxide. The CO2 formed produced carbohydrate in the Calvin cycle.

Question:12

Why is RuBisCo enzyme the most abundant enzyme in the world?

Answer:

The RuBisCo enzyme is found in abundance in nature. It acts as a catalyst in the process of producing sugar from carbon dioxide. The enzyme is present in all the plants performing photosynthesis. The enzyme is responsible for deriving the carbon dioxide of the biosphere from the carbon fixation activities. Therefore, it found everywhere around us.

Question:13

Why does not photorespiration take place in C4 plants?

Answer:

The bundle sheath present in the C4 plants help in accelerating the carbon dioxide concentration in the plant body. The RuBisCo binding is a competitive process which depends on the concentration of oxygen or carbon dioxide. If the concentration of carbon dioxide is more, the enzyme would actively bind it and result in the respective compounds, leaving the oxygen molecules. Thus, the process of photorespiration does not occur in C4 plants.

Also, check NCERT Solutions for Class 11 Other Subjects

NCERT Exemplar Class 11 Biology Solutions Chapter 13 Photosynthesis in Higher Plants - Main Subtopics:

· Photosynthesis

· Early experiments

· Where does photosynthesis take place?

· Pigments involved in photosynthesis

· Light reaction

· The electron transports

· ATP and NADPH usage

· The C4 pathway

· Photorespiration

· Factors affecting photosynthesis

What will students learn in NCERT Exemplar Class 11 Biology Solutions Chapter 13?

NCERT Exemplar solutions for Class 11 Biology chapter 13 plays an important role for students who wish to take up botany as a part of their further studies. It deals with the process of how plants make their own food and all of the necessary ingredients, types and reactions which contribute to it.

You must have noticed different shades of green in leaves. Ever thought why does this colour variation take place? It is due to four types of pigments, namely chlorophyll a, chlorophyll b, xanthophylls and carotenoids. At specific wavelengths light is absorbed by pigments and as a result, colour variation takes place.

NCERT Exemplar Class 11 Biology Solutions Chapter Wise:

Important Topics of NCERT Exemplar Class 11 Biology Solutions Chapter 13 Photosynthesis in Higher Plants:

Class 11 Biology NCERT Exemplar solutions chapter 13 has explained that Photosynthesis, Early experiments which tested photosynthesis, where photosynthesis takes place, Pigments involved in photosynthesis, Light reaction, ATP and NADPH usage, The C4 pathway, Photorespiration, Factors affecting photosynthesis are important topics which students should pay extra attention to.

NCERT Exemplar Class 11 Biology Solutions Chapter 13 also covers light reaction. All of these topics are important in this chapter.

NCERT Exemplar Class 11 Solutions:

NEET Highest Scoring Chapters & Topics
Most Scoring concepts For NEET (Based On Previous Year Analysis)
Download EBook

Check Chapter-Wise Solutions of Questions Given in Book:

Also, Read NCERT Solution subject wise

Must Read NCERT Notes subject wise

Also Check NCERT Books and NCERT Syllabus here

Frequently Asked Questions (FAQs)

1. Is this chapter important for higher studies?

Yes, those who want to pursue higher education in botany and other related fields should focus on this chapter.

2. How are these solutions helpful?

Learners can understand the accepted answering pattern and can also revise the entire chapter from the NCERT exemplar Class 11 Biology solutions chapter 13. 

3. How many questions are solved in this chapter?

A total of 9 questions are solved from this chapter are given in the main exercise after the chapter and theory are complete in Class 11 Biology NCERT exemplar solutions chapter 13. 

4. What types of questions are asked from this chapter?

From this chapter, students are asked application-based, comprehension based, and evaluation type questions.

Articles

Get answers from students and experts

A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

Option 1)

0.34\; J

Option 2)

0.16\; J

Option 3)

1.00\; J

Option 4)

0.67\; J

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times.  Assume that the potential energy lost each time he lowers the mass is dissipated.  How much fat will he use up considering the work done only when the weight is lifted up ?  Fat supplies 3.8×107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate.  Take g = 9.8 ms−2 :

Option 1)

2.45×10−3 kg

Option 2)

 6.45×10−3 kg

Option 3)

 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

Back to top