Selina Concise Class 9 Biology Solution Chapter No. 7 ‘Respiration in Plants’ For ICSE Board Students
Respiration in Plants
A)
1) Answer: c) in which glucose is broken down into pyruvate.
The glucose breakdown to carbon dioxide and water will not occur in single step. It occurs in series of steps that includes two major steps. In the glycolysis process the glucose is converted into pyruvate.
2) Answer: b) Stomata and lenticels.
Most of the plants function is performed by stomata of leaves and lenticels of stem.
3) Answer: d) Baker’s yeast.
The organisms like certain bacteria and fungi are microscopic and normally respire anaerobically.
B)
1) Answer:
Yes, the plants do respire all the day and all the night. The respiration process is an essential process in all the living organisms.
2) Answer:
- a) Adenosine triphosphate
- b) Respiration
- c) Bacteria, fungus
- d) Glycolysis
- e) Oxygen
- f) Soda lime
3) Answer:
- a) False
- b) False
- c) True
- d) False
C) Answer:
The energy liberated is respiration is not all in the form of heat. The large part of this energy is converted in the form of Adenosine triphosphate or ATP (into chemical substance).
2) Answer:
It is difficult to demonstrate respiration in green plants because there is no evolution of CO2 during day time. Both photosynthesis and respiration process occurs in green plants at day time. Carbon dioxide evolution is indicator to demonstrate respiration among plants.
3) Answer:
In photosynthesis, CO2 is consumed and in respiration CO2 is given out. Where in respiration, O2 is consumed and in photosynthesis O2 or oxygen is released. Therefore, Respiration is said to be the reverse of photosynthesis.
4) Answer:
The plants which are underground have benefits. Underground plants get enough oxygen for the respiration process. And tilling helps soil to become porous and airy. So, the tilling will provide fast growth to the plants.
5) Answer:
ATP: Adenosine Triphosphate
ADP: Adenosine Diphosphate
6) Answer:
For the respiration process, plant requires active enzymes. The enzymes become inactive at high temperature. So the cell respiration cannot occur in any organism at 65° C temperature.
7) Answer:
a) Lenticels are the openings found on older stem.
b) Glycolysis occurs in the Cytoplasm of the cells.
c) Glucose is a respiratory substance.
d) Rate of photosynthesis is more than the rate of respiration in the case of green plants.
e) Pyrogallate of potash is a chemical which absorbs oxygen of the air.
f) KOH (caustic potash) is used to create vacuum to show anaerobic respiration.
D)
1) Answer:
To perform various activities of the body all living cells of the plant need or require energy. The energy which is produced by the breakdown of simple carbohydrate or glucose is called as respiration. In some cases, respiration is compared with the burning like burning of coal. The respiration and burning liberate energy and gives CO2 and water as end product.
If we compare respiration and burning the following are differences:
The respiration process is cellular process and burning is non-cellular process. The burning occurs at high temperature but the respiration occurs at body temperature. The respiration takes place in series of chemical steps where burning takes place in a single step.
The energy which is liberated as ATP and some heat in respiration. All the energy is liberated as heat and light in burning. In respiration, no light energy is produced and in burning light energy is produced.
2) Answer:
Differences between aerobic and anaerobic respiration:
Aerobic respiration |
Anaerobic respiration |
When respiration takes place only in the presence of oxygen then it is called as Aerobic respiration | When respiration takes place in the absence of oxygen then it is called as Anaerobic respiration. |
The process uses oxygen. | The process do not uses oxygen. |
It is complete breakdown of glucose. | It is incomplete breakdown of glucose. |
The end product of aerobic respiration are carbon dioxide and water. | The end product of anaerobic respiration are ethyl alcohol and carbon dioxide. |
Liberated energy in 38 ATP (large quantity) from one mole of glucose. | Liberated energy in 2 ATP (Small quantity) from one mole of glucose. |
The aerobic respiration proceeds normally throughout life. | The anaerobic respiration proceeds temporarily for short periods. |
3) Answer:
To prove, carbon dioxide is produced during respiration in germinating seed experiment below:
- Take two flasks and name them ‘A’ ‘B’.
- At the bottom of each flask, place wet cotton wool.
- In the flask ‘A’ soaked seed should be placed and in flask ‘B’ boiled or dead seed should be placed. To prevent bacterial growth on dead seed, we need to use antiseptic like carbolic acid.
- Cork the flask and keep them in similar conditions of light and temperature.
- After few days, bottle ‘A’ shows germinated seeds and bottle ‘B’ do not show anything.
- The gases of each flasks were tested by removing cork and tilting flask over the test tube which contains limewater and then shake the test tube.
- Flask ‘A’ shows presence of CO2 and limewater turns milky. Hence, germinating seeds give out CO2 and Flask ‘B’ will show no effect.
4) Answer:
- Lenticels do help stem in the participation in respiration process.
- Stomata do help leaves in the participation in respiration.
- The root hairs do help the roots in the participation in respiration.
E)
1)
a)
b)
i) a) 6H2O, b) C2H2OH
ii) a) Is aerobic respiration, b) Is anaerobic respiration.
iii)Reaction (a) can occur only in the presence of oxygen, the reaction (b) can complete on the absence of oxygen.
2.
a) Answer: The CO2 absorbed by KOH. To check the presence of CO2, potassium hydroxide solution is kept in test tube X and Y.
b) Answer: Due to consumption of oxygen, the space has been developed. Therefore, the coloured water risen in tubing 1.
c) Answer: After boiling of peas soaked, the boiled seed become dead. The dead seeds cannot respire. Hence, this was the purpose of keeping boiled peas soaked in a disinfectant in test tube Y.
d) Answer: Respiration is the biological process that caused the above rise.
e)Answer: Catabolic is a destructive process. Catabolic process for the energy release for the respiration process is shown in the experiment.
3.
a) Answer: In total five flasks, the different plants parts have been kept.
b) Answer: When CO2 will be produced, the lime water becomes milky. This happens because limewater is responsible for the absorption of CO2 which is present in the flask.
c) Answer: The flasks which contain parts of plant will show respiration by releasing CO2. Flask A, B, C, D, and E containing limewater will turn milky. F flask don’t have plant part that’s why limewater will not change due to absence of respiration.
d) Answer: To control the experiment, the F flask is there and it is different from all the flasks.
e) Answer: During respiration process, the CO2 or carbon dioxide is produced. Hence, this is the conclusion of this experiment.
4.
a) Answer: The given experiment is to study or prove that carbon dioxide or CO2 is produced during respiration in germinating seeds.
b) Answer: The soda lime absorbs CO2 which is present in the air and it is kept in the bottle ‘A’ to check presence of CO2. The limewater will indicate that there is absence CO2 in the bottle B.
c) Answer: The bottle ‘C’ contains germinating seeds. The bottle ‘D’ contains limewater and it shows presence of CO2 due to respiration process. After absorbing CO2, limewater turns milky. This changes are observed in bottle.
d) Answer: C6H12O6 + 6O2.6CO2 + 6H2O + 38ATP (Energy). This is the chemical reaction for above experiment.
e) Answer: The photosynthesis process will not occur in the absence of light. So, if bottle ‘C’ will be covered by black cloth then the photosynthesis will not take place. Therefore, Process of respiration will be observed.
f) Answer: The thermometer were introduced in bottle ‘C’ to observe changes in the temperature. In the presence of respiration process, the temperature will rise and in the absence of respiration, temperature will not rise. Hence, this was observed.