Selina Textbook Solutions: Respiration in Plants | Biology Class 9 ICSE PDF Download

 Page 1


Chapter 7. Respiration in Plants
Exercise 1
Solution A.
1. (c) in which glucose is broken down into pyruvate
2. (b) Stomata and lenticels
3. (d) Baker’s yeast
Solution B.1.
Respiration is an essential life process for all living organisms. Therefore, plants also 
respire all day and all night.
Solution B.2.
(a) ATP 
(b) Respiration 
(c) Fungus 
(d) Glycolysis 
(e) Oxygen 
(f) Soda lime
Solution B.3.
(a) False. Aerobic respiration of one mole of glucose yields 38 ATP. 
(b) False. Anaerobic respiration in plants yields ethanol. 
(c) True 
(d) False. All leaves of a green plant normally respire aerobically at night.
Solution C.1.
The energy liberated in respiration is stored in the form of ATP inside the cells. Some part 
of it is lost as heat to the surroundings.
Solution C.2.
During day time, both photosynthesis and respiration takes place in green plants. 
Evolution of CO
2 
is an indicator to demonstrate respiration in living organisms. 
CO
2
 produced during respiration in plants gets utilized during photosynthesis and thus, 
there is no evolution of CO
2
. Therefore, it is difficult to demonstrate respiration in green 
plants as there is no evolution of CO
2
 during day time.
Solution C.3.
Respiration is said to be the reverse of photosynthesis due to the following reasons:
Page 2


Chapter 7. Respiration in Plants
Exercise 1
Solution A.
1. (c) in which glucose is broken down into pyruvate
2. (b) Stomata and lenticels
3. (d) Baker’s yeast
Solution B.1.
Respiration is an essential life process for all living organisms. Therefore, plants also 
respire all day and all night.
Solution B.2.
(a) ATP 
(b) Respiration 
(c) Fungus 
(d) Glycolysis 
(e) Oxygen 
(f) Soda lime
Solution B.3.
(a) False. Aerobic respiration of one mole of glucose yields 38 ATP. 
(b) False. Anaerobic respiration in plants yields ethanol. 
(c) True 
(d) False. All leaves of a green plant normally respire aerobically at night.
Solution C.1.
The energy liberated in respiration is stored in the form of ATP inside the cells. Some part 
of it is lost as heat to the surroundings.
Solution C.2.
During day time, both photosynthesis and respiration takes place in green plants. 
Evolution of CO
2 
is an indicator to demonstrate respiration in living organisms. 
CO
2
 produced during respiration in plants gets utilized during photosynthesis and thus, 
there is no evolution of CO
2
. Therefore, it is difficult to demonstrate respiration in green 
plants as there is no evolution of CO
2
 during day time.
Solution C.3.
Respiration is said to be the reverse of photosynthesis due to the following reasons:
1. In respiration, the organic food is broken down into its inorganic compounds, i.e., 
CO
2
 and H
2
O, while in photosynthesis the organic food is synthesized from its 
inorganic components, i.e., CO
2
 and H
2
O.
2. In respiration, CO
2
 is given out, while in photosynthesis CO
2
 is consumed.
3. In respiration, O
2
 is consumed, while in photosynthesis O
2
 is released or evolved.
4. In respiration, energy is liberated, while in photosynthesis energy is absorbed.
Solution C.4.
illing makes the soil porous and airy. The underground parts of the plants get sufficient 
amount of oxygen for respiration. In this way, tilling helps the crops to grow faster.
Solution C.5.
ATP: Adenosine triphosphate 
ADP: Adenosine diphosphate
Solution C.6.
Cell respiration cannot occur in any organism at a temperature of about 65°C because 
the enzymes involved in respiration become inactivated at high temperatures.
Solution C.7.
(a) Lenticels 
(b) Cytoplasm 
(c) Glucose 
(d) Photosynthesis, respiration 
(e) Pyrogallate of potash 
(f) KOH (caustic potash)
Solution D.1.
Oxidation of organic food particularly carbohydrates in living cells to release energy is 
called respiration.
Similarities between respiration and burning:
1. Both require oxygen
2. Both produce energy
3. Both result in the formation of CO
2
 and water
Differences between respiration and burning: 
Respiration Burning
1. Occurs in a series of chemical 
steps
1. Occurs in a single step
2. Carried out by enzymes 2. Carried out by heat
3. Biochemical process 3. Physico-chemical process
Page 3


Chapter 7. Respiration in Plants
Exercise 1
Solution A.
1. (c) in which glucose is broken down into pyruvate
2. (b) Stomata and lenticels
3. (d) Baker’s yeast
Solution B.1.
Respiration is an essential life process for all living organisms. Therefore, plants also 
respire all day and all night.
Solution B.2.
(a) ATP 
(b) Respiration 
(c) Fungus 
(d) Glycolysis 
(e) Oxygen 
(f) Soda lime
Solution B.3.
(a) False. Aerobic respiration of one mole of glucose yields 38 ATP. 
(b) False. Anaerobic respiration in plants yields ethanol. 
(c) True 
(d) False. All leaves of a green plant normally respire aerobically at night.
Solution C.1.
The energy liberated in respiration is stored in the form of ATP inside the cells. Some part 
of it is lost as heat to the surroundings.
Solution C.2.
During day time, both photosynthesis and respiration takes place in green plants. 
Evolution of CO
2 
is an indicator to demonstrate respiration in living organisms. 
CO
2
 produced during respiration in plants gets utilized during photosynthesis and thus, 
there is no evolution of CO
2
. Therefore, it is difficult to demonstrate respiration in green 
plants as there is no evolution of CO
2
 during day time.
Solution C.3.
Respiration is said to be the reverse of photosynthesis due to the following reasons:
1. In respiration, the organic food is broken down into its inorganic compounds, i.e., 
CO
2
 and H
2
O, while in photosynthesis the organic food is synthesized from its 
inorganic components, i.e., CO
2
 and H
2
O.
2. In respiration, CO
2
 is given out, while in photosynthesis CO
2
 is consumed.
3. In respiration, O
2
 is consumed, while in photosynthesis O
2
 is released or evolved.
4. In respiration, energy is liberated, while in photosynthesis energy is absorbed.
Solution C.4.
illing makes the soil porous and airy. The underground parts of the plants get sufficient 
amount of oxygen for respiration. In this way, tilling helps the crops to grow faster.
Solution C.5.
ATP: Adenosine triphosphate 
ADP: Adenosine diphosphate
Solution C.6.
Cell respiration cannot occur in any organism at a temperature of about 65°C because 
the enzymes involved in respiration become inactivated at high temperatures.
Solution C.7.
(a) Lenticels 
(b) Cytoplasm 
(c) Glucose 
(d) Photosynthesis, respiration 
(e) Pyrogallate of potash 
(f) KOH (caustic potash)
Solution D.1.
Oxidation of organic food particularly carbohydrates in living cells to release energy is 
called respiration.
Similarities between respiration and burning:
1. Both require oxygen
2. Both produce energy
3. Both result in the formation of CO
2
 and water
Differences between respiration and burning: 
Respiration Burning
1. Occurs in a series of chemical 
steps
1. Occurs in a single step
2. Carried out by enzymes 2. Carried out by heat
3. Biochemical process 3. Physico-chemical process
4. Energy is liberated in the form of 
ATP and some heat
4. Energy is liberated in the form of 
heat and light
5. No light energy is produced 5. Light energy is produced
6. Cellular process 6. Non-cellular process
7. Occurs at body temperature
7. Occurs at high temperature (at 
ignition point)
8. No supply of heat energy is 
required
8. Supply of heat energy is required
9. The organic compound is oxidized 
to carbon dioxide and water.
9. The organic compound initially 
chars and later burns, producing a 
flame.
Solution D.2.
Difference between aerobic and anaerobic respiration in plants: 
Aerobic respiration in plants Anaerobic respiration in plants
1. Also called oxybiotic respiration 1. Also called anoxybiotic respiration
2. Proceeds in the presence of 
oxygen
2. Proceeds in the absence of 
oxygen
3. Occurs in mitochondria 3. Occurs in cytoplasm
4. Complete breakdown of glucose 4. Incomplete breakdown of glucose
5. End-products are carbon dioxide 
and water
5. End-products are ethyl alcohol 
and carbon dioxide
6. Large quantity of energy is 
liberated (38ATP) from one mole of 
glucose
6. Small quantity of energy is 
liberated (2ATP) from one mole of 
glucose
7. Occurs normally throughout the 
life
7. Occurs temporarily for short 
periods
Solution D.3.
(a) Experiment demonstrating that germinating seeds produce heat.
1. Take two thermos flasks ‘A’ and ‘B’.
2. Take about 200 bean or pea seeds and soak them in water for more than 24 hours.
3. Divide the seeds into two equal groups. Kill one group of seeds by boiling them and 
then, wash them with dilute formalin to prevent bacterial decay. Place the live 
germinating seeds in flask A and the killed one in flask B.
4. Insert a thermometer in each of the flasks and plug their mouths with cotton wool. 
Note the initial reading in the thermometer.
5. After few hours, the thermometer in flask A will show a higher reading indicating 
that the germinating seeds produce heat. There will not be any rise in the 
Page 4


Chapter 7. Respiration in Plants
Exercise 1
Solution A.
1. (c) in which glucose is broken down into pyruvate
2. (b) Stomata and lenticels
3. (d) Baker’s yeast
Solution B.1.
Respiration is an essential life process for all living organisms. Therefore, plants also 
respire all day and all night.
Solution B.2.
(a) ATP 
(b) Respiration 
(c) Fungus 
(d) Glycolysis 
(e) Oxygen 
(f) Soda lime
Solution B.3.
(a) False. Aerobic respiration of one mole of glucose yields 38 ATP. 
(b) False. Anaerobic respiration in plants yields ethanol. 
(c) True 
(d) False. All leaves of a green plant normally respire aerobically at night.
Solution C.1.
The energy liberated in respiration is stored in the form of ATP inside the cells. Some part 
of it is lost as heat to the surroundings.
Solution C.2.
During day time, both photosynthesis and respiration takes place in green plants. 
Evolution of CO
2 
is an indicator to demonstrate respiration in living organisms. 
CO
2
 produced during respiration in plants gets utilized during photosynthesis and thus, 
there is no evolution of CO
2
. Therefore, it is difficult to demonstrate respiration in green 
plants as there is no evolution of CO
2
 during day time.
Solution C.3.
Respiration is said to be the reverse of photosynthesis due to the following reasons:
1. In respiration, the organic food is broken down into its inorganic compounds, i.e., 
CO
2
 and H
2
O, while in photosynthesis the organic food is synthesized from its 
inorganic components, i.e., CO
2
 and H
2
O.
2. In respiration, CO
2
 is given out, while in photosynthesis CO
2
 is consumed.
3. In respiration, O
2
 is consumed, while in photosynthesis O
2
 is released or evolved.
4. In respiration, energy is liberated, while in photosynthesis energy is absorbed.
Solution C.4.
illing makes the soil porous and airy. The underground parts of the plants get sufficient 
amount of oxygen for respiration. In this way, tilling helps the crops to grow faster.
Solution C.5.
ATP: Adenosine triphosphate 
ADP: Adenosine diphosphate
Solution C.6.
Cell respiration cannot occur in any organism at a temperature of about 65°C because 
the enzymes involved in respiration become inactivated at high temperatures.
Solution C.7.
(a) Lenticels 
(b) Cytoplasm 
(c) Glucose 
(d) Photosynthesis, respiration 
(e) Pyrogallate of potash 
(f) KOH (caustic potash)
Solution D.1.
Oxidation of organic food particularly carbohydrates in living cells to release energy is 
called respiration.
Similarities between respiration and burning:
1. Both require oxygen
2. Both produce energy
3. Both result in the formation of CO
2
 and water
Differences between respiration and burning: 
Respiration Burning
1. Occurs in a series of chemical 
steps
1. Occurs in a single step
2. Carried out by enzymes 2. Carried out by heat
3. Biochemical process 3. Physico-chemical process
4. Energy is liberated in the form of 
ATP and some heat
4. Energy is liberated in the form of 
heat and light
5. No light energy is produced 5. Light energy is produced
6. Cellular process 6. Non-cellular process
7. Occurs at body temperature
7. Occurs at high temperature (at 
ignition point)
8. No supply of heat energy is 
required
8. Supply of heat energy is required
9. The organic compound is oxidized 
to carbon dioxide and water.
9. The organic compound initially 
chars and later burns, producing a 
flame.
Solution D.2.
Difference between aerobic and anaerobic respiration in plants: 
Aerobic respiration in plants Anaerobic respiration in plants
1. Also called oxybiotic respiration 1. Also called anoxybiotic respiration
2. Proceeds in the presence of 
oxygen
2. Proceeds in the absence of 
oxygen
3. Occurs in mitochondria 3. Occurs in cytoplasm
4. Complete breakdown of glucose 4. Incomplete breakdown of glucose
5. End-products are carbon dioxide 
and water
5. End-products are ethyl alcohol 
and carbon dioxide
6. Large quantity of energy is 
liberated (38ATP) from one mole of 
glucose
6. Small quantity of energy is 
liberated (2ATP) from one mole of 
glucose
7. Occurs normally throughout the 
life
7. Occurs temporarily for short 
periods
Solution D.3.
(a) Experiment demonstrating that germinating seeds produce heat.
1. Take two thermos flasks ‘A’ and ‘B’.
2. Take about 200 bean or pea seeds and soak them in water for more than 24 hours.
3. Divide the seeds into two equal groups. Kill one group of seeds by boiling them and 
then, wash them with dilute formalin to prevent bacterial decay. Place the live 
germinating seeds in flask A and the killed one in flask B.
4. Insert a thermometer in each of the flasks and plug their mouths with cotton wool. 
Note the initial reading in the thermometer.
5. After few hours, the thermometer in flask A will show a higher reading indicating 
that the germinating seeds produce heat. There will not be any rise in the 
temperature of flask B. 
(b) Experiment demonstrating that germinating seeds give out carbon dioxide.
1. Take two flasks ‘A’ and’ B’.
2. Place some wet cotton wool at the bottom of both the flasks.
3. Place some soaked seeds of pea in flask A and an equal number of boiled or dead 
seeds in flask B. Add some carbolic acid to flask B to prevent the growth of bacteria 
on dead seeds.
4. Cork the flasks and keep them undisturbed for few days.
5. After few days, the seeds in flask A will have germinated and the seeds in flask B 
do not show any signs of germination.
6. The gases in each of the flasks are then tested by removing the cork and tilting the 
flask over a test tube containing limewater and then shaking up the test tube.
7. The expected CO
2
 present in flask A will turn limewater milky showing that 
germinating seeds give out CO
2
, while the gas in flask B will show no effect on 
Page 5


Chapter 7. Respiration in Plants
Exercise 1
Solution A.
1. (c) in which glucose is broken down into pyruvate
2. (b) Stomata and lenticels
3. (d) Baker’s yeast
Solution B.1.
Respiration is an essential life process for all living organisms. Therefore, plants also 
respire all day and all night.
Solution B.2.
(a) ATP 
(b) Respiration 
(c) Fungus 
(d) Glycolysis 
(e) Oxygen 
(f) Soda lime
Solution B.3.
(a) False. Aerobic respiration of one mole of glucose yields 38 ATP. 
(b) False. Anaerobic respiration in plants yields ethanol. 
(c) True 
(d) False. All leaves of a green plant normally respire aerobically at night.
Solution C.1.
The energy liberated in respiration is stored in the form of ATP inside the cells. Some part 
of it is lost as heat to the surroundings.
Solution C.2.
During day time, both photosynthesis and respiration takes place in green plants. 
Evolution of CO
2 
is an indicator to demonstrate respiration in living organisms. 
CO
2
 produced during respiration in plants gets utilized during photosynthesis and thus, 
there is no evolution of CO
2
. Therefore, it is difficult to demonstrate respiration in green 
plants as there is no evolution of CO
2
 during day time.
Solution C.3.
Respiration is said to be the reverse of photosynthesis due to the following reasons:
1. In respiration, the organic food is broken down into its inorganic compounds, i.e., 
CO
2
 and H
2
O, while in photosynthesis the organic food is synthesized from its 
inorganic components, i.e., CO
2
 and H
2
O.
2. In respiration, CO
2
 is given out, while in photosynthesis CO
2
 is consumed.
3. In respiration, O
2
 is consumed, while in photosynthesis O
2
 is released or evolved.
4. In respiration, energy is liberated, while in photosynthesis energy is absorbed.
Solution C.4.
illing makes the soil porous and airy. The underground parts of the plants get sufficient 
amount of oxygen for respiration. In this way, tilling helps the crops to grow faster.
Solution C.5.
ATP: Adenosine triphosphate 
ADP: Adenosine diphosphate
Solution C.6.
Cell respiration cannot occur in any organism at a temperature of about 65°C because 
the enzymes involved in respiration become inactivated at high temperatures.
Solution C.7.
(a) Lenticels 
(b) Cytoplasm 
(c) Glucose 
(d) Photosynthesis, respiration 
(e) Pyrogallate of potash 
(f) KOH (caustic potash)
Solution D.1.
Oxidation of organic food particularly carbohydrates in living cells to release energy is 
called respiration.
Similarities between respiration and burning:
1. Both require oxygen
2. Both produce energy
3. Both result in the formation of CO
2
 and water
Differences between respiration and burning: 
Respiration Burning
1. Occurs in a series of chemical 
steps
1. Occurs in a single step
2. Carried out by enzymes 2. Carried out by heat
3. Biochemical process 3. Physico-chemical process
4. Energy is liberated in the form of 
ATP and some heat
4. Energy is liberated in the form of 
heat and light
5. No light energy is produced 5. Light energy is produced
6. Cellular process 6. Non-cellular process
7. Occurs at body temperature
7. Occurs at high temperature (at 
ignition point)
8. No supply of heat energy is 
required
8. Supply of heat energy is required
9. The organic compound is oxidized 
to carbon dioxide and water.
9. The organic compound initially 
chars and later burns, producing a 
flame.
Solution D.2.
Difference between aerobic and anaerobic respiration in plants: 
Aerobic respiration in plants Anaerobic respiration in plants
1. Also called oxybiotic respiration 1. Also called anoxybiotic respiration
2. Proceeds in the presence of 
oxygen
2. Proceeds in the absence of 
oxygen
3. Occurs in mitochondria 3. Occurs in cytoplasm
4. Complete breakdown of glucose 4. Incomplete breakdown of glucose
5. End-products are carbon dioxide 
and water
5. End-products are ethyl alcohol 
and carbon dioxide
6. Large quantity of energy is 
liberated (38ATP) from one mole of 
glucose
6. Small quantity of energy is 
liberated (2ATP) from one mole of 
glucose
7. Occurs normally throughout the 
life
7. Occurs temporarily for short 
periods
Solution D.3.
(a) Experiment demonstrating that germinating seeds produce heat.
1. Take two thermos flasks ‘A’ and ‘B’.
2. Take about 200 bean or pea seeds and soak them in water for more than 24 hours.
3. Divide the seeds into two equal groups. Kill one group of seeds by boiling them and 
then, wash them with dilute formalin to prevent bacterial decay. Place the live 
germinating seeds in flask A and the killed one in flask B.
4. Insert a thermometer in each of the flasks and plug their mouths with cotton wool. 
Note the initial reading in the thermometer.
5. After few hours, the thermometer in flask A will show a higher reading indicating 
that the germinating seeds produce heat. There will not be any rise in the 
temperature of flask B. 
(b) Experiment demonstrating that germinating seeds give out carbon dioxide.
1. Take two flasks ‘A’ and’ B’.
2. Place some wet cotton wool at the bottom of both the flasks.
3. Place some soaked seeds of pea in flask A and an equal number of boiled or dead 
seeds in flask B. Add some carbolic acid to flask B to prevent the growth of bacteria 
on dead seeds.
4. Cork the flasks and keep them undisturbed for few days.
5. After few days, the seeds in flask A will have germinated and the seeds in flask B 
do not show any signs of germination.
6. The gases in each of the flasks are then tested by removing the cork and tilting the 
flask over a test tube containing limewater and then shaking up the test tube.
7. The expected CO
2
 present in flask A will turn limewater milky showing that 
germinating seeds give out CO
2
, while the gas in flask B will show no effect on 
limewater. 
(c) Experiment demonstrating that germinating seeds can respire even in total 
absence of air.
1. Take few soaked and peeled off pea seeds and push them into the mouth of a test 
tube filled with mercury and inverted in a beaker of mercury. The seeds will float to 
the top and will be completely surrounded by mercury.
2. After few days, the level of mercury falls and the presence of some gas in the test 
tube can be detected.
3. Add some KOH to the test tube. The gas present in the test tube will be absorbed 
and the level of mercury will again rise showing that the gas was CO
2
. Hence, we 
can prove that germinating seeds respire even in the total absence of air.