experiment to show that germinating seeds produce heat

Experiment to Prove that Heat is Evolved during Respiration

Respiration in plants can be investigated by transport out experiments to show the production of carbon dioxide (CO 2 ) and heat and consumption of oxygen. Some amount of energy is generated from the oxidation of food materials is released as heat. This can be proved by germinating seeds.

Requirements: One Thermo flask, some germinating Gram seeds, and a thermometer.

Procedure: Some germinating gram seeds are taken in the Thermo flask and closed its mouth tightly with a cork. A thermometer is introduced through the cork so that its bulb rests among the gram seeds. Note the mercury reading of the thermometer.

Fig: Experiment to Heat is Evolved during Respiration

Experiment to show Oxygen is used during respiration

Put some germinating seeds in a conical flask. With the help of a thread suspend a small tube containing KOH in the flask. Through the hole of the cork, pass a glass tube bent twice at right angles. One end of the tube is in the flask while the other end is in the beaker filled with water. Make the apparatus airtight. Note the level of water in the tube. Keep the apparatus for some time and note the position of water.

It is observed that water rises in the tube. The rise in the level of water is due to a partial vacuum created in the flask because the gas produced during respiration is absorbed by KOH.

This shows that germinating seeds produce CO 2 during aerobic respiration as KOH can absorb CO 2 . This is aerobic respiration as KOH can absorb CO 2 produced by seeds using air available.

The germinating seeds undergo aerobic respiration as they use the oxygen accessible within the conical flask. As entire of the oxygen is used up by the germinating seeds, the pressure in the flask is decreased. Hence, accordingly, the mercury level rises in the far end of the bent glass tube.

• Experiment to prove carbon dioxide is released during germination

Gas produced in flask A turns lime water milky showing carbon dioxide has been produced. Flask B does not turn lime water milky, showing the absence of carbon dioxide, because of boiled seeds.

• Experiment to show heat is evolved during respiration

The live seeds show an increase in the temperature; boiled seeds do not show any increase. Living seeds respire and evolve heat while the boiled seeds do not respire and do not evolve heat.

Observation: After some time an increase in the reading of mercury in the thermometer will be observed. The temperature in the flask with germinating seeds is higher than the temperature of the flask with dry deeds.

Conclusion: Rise of mercury indicates the rise of temperature. And this temperature is produced by the respiration of the germinating seeds. In dry seeds, enzymes are dormant so respiration did not take place and no increase in temperature whereas in germinating seeds enzymes are active and respiration has taken place with the increase in temperature.

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Top 10 Experiments on Respiration | Plants

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The below mentioned article includes a collection of top ten experiments on respiration in plants.

1. Experiment to demonstrate the utility of oxygen in respiration:

Requirements:

A conical flask, a bent tube, germinating seeds, caustic potash in a small container, a mercury dish.

Germinating seeds are taken in a conical flask in which a container of caustic potash is also put. The mouth of this conical flask is closed by a single-holed cork through which a glass tube bent twice at right angles in inserted. The far end of this tube is put in the mercury dish. Now this apparatus is left undisturbed for some time.

Observation:

The mercury in far end of bent glass tube rises to a height of 15 cm.

Explanation:

The germinating seeds undergo aerobic respiration as they use the oxygen available inside the conical flask. As whole of the oxygen is used up by the germinating seeds, the pressure inside the flask is decreased. Hence, consequently the mercury level rises in the far end of the bent glass tube.

This level reaches only a height of 15 cm in the glass tube. As this level is about one-fifth the air. As oxygen constitutes one fifth of total composition, it is reasonable to infer that the seeds have used this gas of the air in respiration.

2. Experiment to demonstrate the energy is production in the form of heat during the respiration:

Thermos bottle (2), cork, thermometer (2), 50 germinating seeds, 50 dry seeds.

1. Take two thermos bottles fitted with a uni-holed cork.

2. In one thermos fill about 50 germinating seeds and in the other fill about 50 dry seeds.

3. Through the hole of the cork, insert a thermometer in each thermos in a way that its bulb is buried in the seeds (Fig. 47).

4. Note the initial temperature in the thermometer and keep them as such for a few hours. Note the final temperature.

Observations:

There is no change in temperature in the thermometer placed in dry seeds while the temperature rises in the another thermometer which is fitted in the thermos containing germinating seeds.

In case of the dry seeds, there is no change in the thermometer reading because they are not undergoing through the process of respiration. But distinct rise in temperature in case of germinating seeds is obviously due to the liberation of heat energy by the respiratory substrate, i.e., germinating seeds.

3. Experiment to demonstrate aerobic respiration:

A few germinating seeds or flower-buds are put in a flask with a cork at the mouth. Care must be taken to remove all the green parts from the flower-buds, other­wise the CO 2 , liberated will be at once utilised in photosynthesis.

A glass tube is fitted through the cork. Now one or two sticks of caustic potash are introduced into the flask. Two cotton plugs are put to keep the flower-buds and the caustic potash sticks in position. The flask with the tube is inverted over a trough of mercury, thus cutting off connec­tion with external air. It is fixed in position with clamp and stand.

After a few hours it is noted that the mercury has risen in the tube covering nearly one-fifth of the total volume. The volume of mercury risen can at its maximum be one-fifth of the entire volume of the flask, for O 2 in the atmosphere is only about 20%.

It is due to the fact that carbon dioxide given out during respiration has been absorbed by caustic potash pro­ducing partial vacuum. Oxygen present in the flask has been utilised for respiration. The gas that remains in the flask is nitrogen.

We know that nearly one-fifth of the volume of air is oxygen. So this experiment, besides showing intake of oxygen and giving out of carbon dioxide, also proven that volume of oxygen taken in is almost equal to the volume of carbon dioxide given out.

4. Experiment to demonstrate anaerobic respiration:

Germinating seeds, a test tube, mercury, KOH crystals, petri dish, etc.

The mercury is filled in the test tube up to the rim. Take a petri dish full of mercury and put the mercury filled test tube in the inverted condition with the help of thumb. The thumb is removed inside the petri dish. Now introduce some seeds (germinating or soaked) in the test tube with the help of a forceps. Let this apparatus be put as such for some time.

After some time the mercury level in test tube goes down. Now introduce some KOH crystals in the above test tube. After a little while the mercury level will go up to the former position.

The lowering of mercury level in test tube indicates that some gas has been released by germinating seeds. Only CO 2 gas may be absorbed by KOH crystals. We see that with the introduction of KOH crystals the level of mercury goes high, hence the seeds have released CO 2 under the anaerobic conditions.

5. Experiment to demonstrate the production of carbon dioxide in aerobic respiration:

Bottle, germinating seeds, cork, stopper, glass tube, water, wide-mouthed tube with a stopcock, lime water.

1. Take a wide-mouthed bottled and place some germinating seeds in it.

2. Close the mouth of the bottle with a two-holed cork.

3. Insert a glass tube, bent twice at right angles, through one of the hole of cork and through the another hole insert a wide-mouthed tube functioning as water reservoir and fitted with a stopcock.

4. Dip the another end of bent glass tube into the water in a beaker (Fig. 43).

5. Keep the experiment as such for a few hours allowing the seeds to respire.

6. Now replace the water-filled beaker with a lime-filled beaker and open the stopcock of water reservoir to allow the water to go in the bottle containing seeds.

After some time the air bubbles come out and the lime water becomes milky.

Lime water turns milky due to the carbon dioxide evolved during the process of germination of seeds. When water is poured by opening the stopcock of water reservoir, it drives out the air through the bent tube, and as the air passes through the lime water, the latter turns milky due to the fact that the air contains carbon dioxide.

6. Experiment t o demonstrate the following in plant respiration by using retort method:

i. That dry seeds to not respire;

ii. That in respiration O 2 absorbed is equal to the CO 2 released; and

iii. That the CO 2 is produced during respiration.

Retorts (3), beakers (3), stands (3), soaked seeds, dry seeds, salt solution, caustic potash solution.

1. Take three retorts and connect them separately with three separate stands.

2. In the bulb of one retort, introduce dry seeds, and dip its tube in a beaker filled with solution of caustic potash (Fig. 45).

3. In the bulb of second retort, introduce soaked seeds, and dip its tube in a beaker containing salt solution.

4. In the bulb of third retort also introduce the soaked seeds and dip its tube in a beaker containing caustic potash solution.

5. Keep the apparatus as such for a few hours and observe.

In the first and second retorts and beakers, there is no change, but in the third apparatus caustic potash solution rises in the tube of retort. Conclusions for all these three conditions can be drawn as follows:

In the first apparatus there is no change because the respiratory susbstrates, i.e., seeds, are dry and not respiring. If the respiration would have been there the CO 2 released would have been absorbed by the caustic potash. Thus, ultimately the solution must have rushed into the tube of retort. So, there is no respiration.

In the second apparatus also, there is no change because the soaked seeds are respiring. They are absorbing oxygen present in the retort and producing nearly equal amount of carbon dioxide. Now because the carbon dioxide, thus released, is insoluble in salt solution, hence there will be no change.

In the third beaker the caustic potash solution rush into the retort tube. It is because of the fact that soaked seeds are respiring. They are absorbing the oxygen and releasing equal amount of carbon dioxide. The carbon dioxide thus released is absorbed by the caustic potash and thus a vacuum is created. To overcome this vacuum, caustic potash solution rushes into the tube, indicating the fact that during respiration CO 2 is produced.

7. Experiment t o determine the Respiratory Quotient (R.Q.) value of the following respiratory substrates with the help of Ganong’s respirometer:

(a) Carbohydrate

(b) Fatty seeds

(c) Organic acids

Ganong’s respirometer, respiratory substrate, saline water, caustic potash, stand, water, filter paper, beaker, balance with weighing box.

1. Pour some water in the lower end of the bulb of respirometer, and on putting a filter paper introduce some germinating seeds (or some other respiratory substrate in the bulb).

2. Now partly fill the respirometer with the saline water. The use of saline water is due to the fact that CO 2 cannot dissolve in it (Fig. 51).

3. Twist the stopper of the bulb in such a way that the two holes come just opposite to each other. In this condition, outside air can pass into the bulbs.

4. Now adjust the level of the leveling tube and graduated tube in a way that saline is present on the same level in both the tubes.

5. Now again twist the stopper in a way that two holes are separated and the bulb is closed.

6. Note the level of the saline water and let the respiratory substrate respire for a few hours.

7. Note the final level. Introduce a caustic potash crystal and note the changes.

(A) If the respiratory substrate is carbohydrate (e.g., wheat, maize, oat, gram, pea, etc.):

Observations and results:

There is no change in the level of saline water because in the carbohydrate the volume of the O 2 absorbed is equal to the volume of CO 2 liberated as shown by the following equation:

CeH 12 O 6 + 6O 2 = 6CO 2 + 6H 2 O + 673 kg cals

R.Q. = 6CO 2 /6O 2 = 1/1 =1

The volume of the CO 2 released can be estimated by adding crystals of KOH. The latter will absorb the CO 2 produced by the seeds resulting ultimately into the rise of the saline level. The volume of the CO 2 can be calculated by deducting the second level from the first one. Suppose it is 35 c.c.

So, R.Q. = Vol. of CO 2 /Vol. of O 2 = 35/35 = 1

(B) If the respiratory substrate is fat, (e.g., mustard or castor seeds):

In case the respiratory substrate is fat, less amount of CO 2 will be released than the O 2 absorbed. A vacuum will be created, and to overcome this vacuum saline level will rise in the tube. This rise will be equal to the excess amount of oxygen. Denote it as V 1 .

It can be shown by the following equation:

4. Dip the lower ends of both the tubes in the water present in the beakers.

5. Fix a thermometer in the apparatus to note the temperature at which the respiration is going on in the material.

6. Keep the stopcocks of both the tubes open and suck out the air with the help of rubber tube till the water in the graduated tubes rises to a pre­determined mark. Initial level in both the tubes should be the same, and note it.

7. Close the stopcock immediately and make the tubes air-tight. Wait for about an hour and note the final levels in the graduated tubes.

8. Take other respiratory substrates, i.e., fats and organic acids and repeat the experiment again as outlined above.

In case of the carbohydrates used as the respiratory substrate, water level remains unchanged in tube A but in tube B it rises.

If the fatty seeds are used as respiratory substrate the water level rises in both the tubes.

In case of organic acids being the respiratory substrate, there is a decrease in water level in tube A while water level rises in tube B.

In case of the carbohydrates, level in tube A remains unchanged indicating that the CO 2 released is equal to the O 2 absorbed in respiration.

In the tube B the level of the water rises because the CO 2 released is absorbed by KOH. By it, the CO 2 amount can be calculated. So, R.Q. is 1.

In case of fats being the respiratory substrate, the level in the tube A increases because more amount of oxygen is absorbed and less amount of CO 2 is released. To overcome this the level rises. Increase in the level of tube B is due to the CO 2 released in respiration. So, R.Q. can be calculated, and it is less than one.

In case of organic acids being the respiratory substrate, the level in tube A decreases indicating the fact that in such cases more amount of CO 2 is released and less amount of O 2 is absorbed in respiration. Increase in level in tube B indicates the amount of CO 2 released in respiration. The result in this case indicates that R.Q. is more than one because C0 2 released is more than the O 2 absorbed in the process.

9. Experiment to demonstrate the respiratory enzymes (oxidase, peroxidase, dehydrogenase and catalase) in the plant tissues:

Potato, petri-dish, gum guaiacum (benzidine), alcohol, water, spirit lamp, hydrogen peroxide, 2, 3, 5- triphenyltetrazolium chloride, test tube, etc.

(A) Oxidase:

1. Cut a thin transverse section of potato with a rajor and put it in a petri-dish.

2. Immerse the section in 2% alcoholic solution of gum guaiacum (benzidine). Wait for about 15 minutes and observe the changes.

3. Take another fresh section of potato, boil it in water and repeat the same procedure mentioned above in points (1) and (2).

(B) Peroxidase:

1. Take another fresh potato section and repeat the same procedure mentioned above in points (1) and (2) for oxidase.

2. After 15 minutes remove all the gum guaiacum (benzidine) solution by adding dilute solution of hydrogen peroxide (3% H 2 O 2 in 30 parts of water).

3. Take another fresh section of potato, boil it in water and repeat the same procedure with it also as mentioned above in points (1) and (2).

(C) Dehydrogenase:

1. To a thin potato section add 0.5% solution of 2, 3, 5, triphenyltetrazolium chloride in a petri-dish and observe the colour.

2. Take another fresh section, boil it with water, repeat the same procedure mentioned above in point (1) and observe.

(D) Catalase:

1. Take a thin potato section, add on it a dilute solution of hydrogen peroxide (1 part of H 2 O 2 in 30 parts of water) and observe the changes.

2. Take another fresh section, boil it with water, repeat the same procedure as mentioned above in point (1) and observe.

Development of blue colour is because of the oxidation of alcoholic solution of gum guaiacum (benzidine).

Blue colour develops as in case of oxidase, but the rapidity, with which the intensity of blue colour develops, is changed. It is because in the presence of H 2 O 2 peroxidases oxidize various substrates such as amines, phenols, etc.

Water is formed when H 2 O 2 gets reacted with hydrogen atoms and electrons in the presence of peroxidase as under:

AH 2 + H 2 O 2 Peroxidase→ A + 2H 2 O

where A = Hydrogen donor

Red colour develops because of the addition of tetrazolium salt.

It is because dehydrogenases remove hydrogen atmos to oxidize the substrate. Such hydrogen atoms are received by the accepters, which thus get reduced.

Bubbles of the oxygen are evolved.

It happens because catalase brings about decomposition of hydrogen peroxide into water as under:

2H 2 O 2 Catalase→ 2H 2 O + O 2

10. Experiment to compare the phenomena of respiration and photosynthesis:

Two long-necked flasks, two mercury- containing troughs, fresh green leaves, flowers, caustic potash crystals, stands (2).

1. Take some freshly-picked green leaves and place them in a long-necked flask.

2. In the another flask place some freshly-picked young flowers.

3. With a little amount of water, moisten the leaves and flowers.

4. Invert both the flasks over separate mercury- containing troughs. Connect both the flasks with stand to hold them in a definite position and keep the whole apparatus in diffused light. (Fig. 50).

5. After about 12 hours, insert a caustic potash crystal in both the flasks and observe.

In the flask containing green leaves there is a little rise in mercury level but sudden and large rise in mercury level is observed in the flask containing young flowers.

In the flask containing green leaves, both photosynthesis as well as respiration are going on simultaneously. The O 2 evolved in the process of photosynthesis is absorbed in the process of respiration. On the contrary the CO 2 released in the respiration is absorbed in the photosynthesis. Because the processes are going on in the diffused light, so the rate of photosynthesis is not very high and some carbon dioxide may accumulate in the flask and may cause a small rise in the mercury level after being absorbed by the caustic potash.

In the flask containing young flowers, sudden and large increase in the mercury level is observed because the process of photosynthesis is absent and, in the respiration process the accumulation of CO 2 is continuously going on in the flask. Caustic potash crystals absorb the CO 2 of the flask, causing the sudden increase in the mercury level.

Related Articles:

• Experiment to Show Carbon Dioxide is Released During Respiration
• Experiments on Respiration in Plants: Top 6 Experiments

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Respiration of germinating seeds (pasport sensors).

Use a carbon dioxide gas sensor to understand the comparative rates of CO₂ gas production for dry, dormant seeds; for wet, germinating seeds at room temperature; and for wet, cold, germinating seeds. Note: This investigation has been updated for Wireless sensors in the Essential Biology lab manual (product number EB-6331)

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Respiration experiments: grade 9 understanding for igcse biology 2.39.

There is a syllabus point in the iGCSE Respiration section that asks candidates to know about an experiment that demonstrates heat production in respiration.  This must be one of the least interesting experiments ever devised but here goes…..

Respiration is the chemical process occurring in all cells in which food molecules are oxidised to release energy for the cell.  Cells need energy for a whole variety of things – active transport of molecules across the cell membrane, muscle contraction, movement of materials around the cytoplasm, cell division, many metabolic reactions etc.   In fact, much of the energy released from glucose molecules in respiration is not “useful energy” for the cell but is given off as heat , a waste product.  In warm-blooded animals such as humans, this heat energy is used to maintain our body temperature at around 37 degrees Celsius.

How can you demonstrate heat production in respiration?

The germinating seeds in the vacuum flask on the left are respiring because they are alive.  The boiled seeds in the vacuum flask on the right will not be respiring because they are dead – boiling will denature all the enzymes needed for metabolism,   The thermometer on the left will show a rise in temperature, the one on the right will stay the same.  The flask on the right with the boiled seeds is a control.  Vacuum flasks are used to insulate the seeds and so prevent heat loss.

The experiment is as simple as that.  If the examiners wanted to ask a question on this, I guess they would give you the set up, ask about the design of the experiment, ask about which variables you might control and perhaps what conclusions could be drawn.

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Describe one experiment each you would perform to demonstrate the following phenomena: ​ The germinating seeds ​ 1. Produce heat.

Aim: experiment demonstrating the fact that germinating seeds produce heat.​ procedure: name two thermal flasks and label them as ‘a’ and ‘b’. approximately 200 pea seeds or beans would be used in the experiment. soak them in water for more than 24 hours split the seeds into two equal groups. the first group of seeds is boiled and killed. dilute formalin or carbolic acid is used to prevent bacterial decay. the live germinating seeds need to be placed in flask a and the boiled/killed seeds in flask b. introduce a thermometer into each of the flasks and seal their mouths with cotton wool. take note of the initial reading observed in the thermometer.​observed in the thermometer.​ observation: a few hours later, the thermometer in the flask a shows a higher reading indicating that the germinating seed generate heat. ​flask b shows no rise in the temperature. conclusion : the germinating seeds are living, respiring, and produce heat..

ICSE Class 9 Biology Solutions Chapter 7 Respiration in Plants

Class 9th icse biology solutions chapter 7 respiration in plants.

Progress Check

Question 1. What are the three important aspects about the overall chemical equation of respiration, pertaining to the following ? (i) Single or several steps (ii) Direct or enzyme-catalysed (iii) Forms of energy liberated Answer: The overall reaction of respiration is C 6 H 12 O 6 → C 2 H 5 OH + 2CO 2 + 2ATP (i) It occurs in several steps. (ii) It is an enzyme catalysed process. (iii) The energy is liberated in the form of ATP and heat.

Question 2. List three ways in which respiration is different from burning : (i) …………………… (ii) ………………….. (iii) ……………………. Answer:

Question 3. Name the three inlets of oxygen for respiration in the plants. (i) ………………….. (ii) …………………… (iii) …………………… Answer: The three inlets of oxygen for respiration in plants are: 1. Stomata in leaves. 2. Lenticels in stem. 3. General surface of the roots.

Question 1. Give the overall chemical equations of the two kinds of respiration in plants : (i) Aerobic (ii) Anaerobic. Answer: (i) Aerobic respiration : When the respiration takes place in the presence of oxygen and there is complete oxidation of glucose with the formation of CO 2 and H 2 O. This is called aerobic respiration C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O + 38ATP

(ii) Anaerobic respiration : Sometimes the plants may temporarily respire even in the absence of oxygen. This type of respiration is called anaerobic respiration. C 6 H 12 O 6 → 2C 2 H 5 OH + 2CO 2 + 2ATP.

Question 2. Mention any one difference other than those reflected In the two chemical equations given above. Answer: The aerobic respiration normally occurs throughout life while anaerobic respiration occurs for short periods.

Question 3. Certain organisms respire only anaerobically throughout their lives. Name any two such organisms. (i) ………………….. (ii) ……………… Answer: (i) Mangroves plants (ii) Forsk (avicenna marina) (ii) Certain Bacteria and fungi are the organisms which respire anaerobically throughout life.

Question 1. In experiments on respiration, the seeds taken as control are boiled. Why? Answer: The boiled seeds are taken as control reaction because they cannot respire. Therefore, no absorption of 02 hence, no respiration takes place.

Question 2. What is the use of the following in experiments on respiration? (i) Soda lime ……………………. ……………………………………….. (ii) Limewater …………………… ………………………………………… Answer: (i)Soda lime : It absorbs the CO 2 produced during respiration or removes CO 2 , from air passes through it.

(ii) Lime water : When CO 2 passes through it, it turn milky showing the presence of CO 2 .

Question 3. Suppose we conduct an experiment to demonstrate respiration in a green plant. What special precaution is required to be taken in it? Answer: The special precaution required to be taken is that the experiment should be carried out in dark or in the bell jar in which the plant is kept should be covered by a black, cloth to prevent photosynthesis.

Question 4. In the experiment No. 5 we are using mercury in the test-tube and beaker. Why can’t we use water instead? Answer: In the experiment we can’t use water instead of mercury because CO 2 produced during experiment will be dissolved in water and it will influence the result of the experiment.

Question 1. Fill in the blanks : In anaerobic respiration in plants, the end product is …………………. and ……………… instead of lactic ……………. in animals. Answer: In anaerobic respiration in plants, the end product is ethyl alcohol and carbon dioxide instead of lactic acid in animals.

Question 2. The table below is intended to give certain differences between photosynthesis and respiration, but a few points are given wrongly. Strike out the wrong ones and write the correct words instead

Review Questions

A. Multiple Choice Type :

Question 1. Glycolysis is a process (a) in which glycogen is broken down into glucose (b) which occurs in mitochondria (c) in which glucose is broken down into pyruvate (d) that occurs next to Krebs cycle. Answer: (c) in which glucose is broken down into pyruvate

Question 2. One same common function is performed by? (a) Stomata and veins (b) Stomata and lenticels (c) Lenticels and sepals (d) Lenticels and hydathodes Answer: (b) Stomata and lenticels

Question 3. Anaerobic respiration normally occurs in (a) Grass, (b) Cactus, (c) Coconut, (d) Baker’s yeast Answer: (d) Baker’s yeast

B. Very Short Answer Type

Question 1. Do the plants respire all day and all night or only at night? Answer: Respiration is must in living organisms. Therefore, plants respire all day and all night.

Question 2. Name the following : (a) Energy currency of cell. (b) Oxidative breakdown of carbohydrates to release energy. (c) An organism which respires throughout life anaerobically. (d) A common phase is both aerobic and anaerobic respiration. (e) Aerobic respiration requires ………………… (f) A chemical which removes CO 2 from the air. Answer: (a) ATP (b) Respiration (c) Fungi (d) Glycolysis (e) Oxygen (f) Soda lime.

Question 3. Mention if the following statements are true or false. If false rewrite them correctly. (a) Aerobic respiration of one mole of glucose yields 138 ATP. (b) Anaerobic respiration in plants yields lactic acid. (c) Carbon dioxide readily dissolves in lime water. (d) All leaves of a green plant, normally respire anaerobically at night. Answer: (a) False- (i) 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 during night.

C. Short Answer Type

Question 1. What happens to the energy liberated in respiration? Answer: The energy liberated in respiration is stored in the form of ATP inside the cells. Some part of it is lost as heat.

Question 2. Why is it usually difficult to demonstrate respiration in green plants? Answer: During day time, both photosynthesis and respiration take place in green plants. The CO 2 produced during respiration gets consumed in 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.

Question 3. Explain why respiration is said to be the reverse of photosynthesis? Answer: Respiration is said to be the reverse of photosynthesis due to the following reasons :

• In respiration the organic food is broken down into it’s 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.
• In respiration CO 2 is given out while in photosynthesis CO 2 is consumed.
• In respiration O 2 is consumed while in photosynthesis O 2 is released or evolved.
• In respiration energy is liberated, while in photosynthesis energy is absorbed.

Question 4. How is the tilling of the soil useful for the crops growing in it? Answer: Tilling makes the soil porous and airy. The underground parts of the plants get sufficient amount of oxygen for respiration. In this way, the tilling helps the plant to grow fast.

Question 5. Write the full form of ATP and ADP. Answer: ATP – Adenosine triphosphate. ADP – Adenosine diphosphate.

Question 6. Can cell respiration occur in any organism at a temperature of about 65°C. Give a reason. Answer: The cell respiration cannot occur in any organism at a temperature of about 65°C because the enzymes involved in respiration becomes inactivated at high temperature.

Question 7. Fill in the blanks : (a) …………….. are the openings found on older stems. (b) Glycolysis occurs in the …………….. of the cells. (c) ……………. is a respiratory substance. (d) Rate of ………………. is more than the rate of ……………. in the daytime in case of green plants. (e) …………….. is a chemical which absorbs oxygen of the air. (f) ……………. is used to create vacuum to show anaerobic respiration. Answer: (a) Lenticels (b) Cytoplasm (c) Glucose (d) Photosynthesis, respiration (e) Chloroform and Acetone (f) Formaldehyde

D. Long Answer Type

Question 1. What is respiration? How are respiration and burning similar and how are they different? Answer: The oxidation of organic food, particularly, carbohydrates in the living cells to release energy is called respiration. Similarities between respiration and burning : (i) Both require oxygen. (ii) Both produce energy. (iii) Both results in the formation of CO 2 and water.

Question 2. How are aerobic and anaerobic respiration different in plants. Answer:

Question 3. Describe one experiment each you would perform to demonstrate the following phenomena : The germinating seeds (a) produce heat, (b) give out carbon dioxide (c) can respire even in total absence of air. Answer: (a) Experiment demonstrating that the germinating seeds produce heat. Take two thermos flasks ‘A’ and ‘B’ Take about 200 seeds (bean or pea) and soak them in water for more than 24 hours. 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.

The gases in each flasks are then tested by removing the cork and tilting the flask over a test tube containing lime water and then shaking up the test tube. The expected CO 2 present in flask (A) will turn lime water milky showing that germinating seeds give out CO 2 While the gas in flask (B) will show no effect in lime water.

Put some KOH in the test tube. You will see that 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, proved that the germinating seeds respire even in the total absence of air.

Question 4. How do the following structures help in respiration in plants? (a) Lenticels ……………….. (b) Stomata ………………….. (c) Root hairs …………………. Answer: (a) Lenticels help the stem to participate in respiration. (b) Stomata – Leaves. (c) Root hairs – Roots.

E. Structured / Application / Ski 11 Type

(b) Lime water absorb CO 2 present in the flask. If Co 2 is produced, the lime water turns milky.

(c) All the five flask containing plant parts will show respiration and thus, the tubes containing lime water will turn milky. Whereas, the flask F containing no plant part will remain as such i.e. there will be no change.

(d) Set up F is a control experiment.

(e) It is concluded from this experiment that CO 2 is produced during respiration.

Question 2. The following two chemical reactions are supposed to indicate a certain process occurring in the green plants under two different conditions : (a) C 6 H 12 O 6 + 6O 2 → 6CO 2 + ……..+ 38ATP (b) C 6 H 12 O 6 →…… + 2CO 2 + 2ATP (i) Fill in the blank in each reaction. (ii) Name the process represented by the two chemical equations. (iii) What are the conditions under which the two reactions (a) and (b) are occurring respectively? Answer: (a) (i) H 2 0 (ii) C 2 H 5 OH

(b) (i) Aerobic respiration (ii) Anaerobic respiration (iii) The reaction (1) can be completed only in the presence of oxygen while reaction (2) can be completed in the absence of oxygen.

(b) When the process of respiration takes place in test tube X, the O 2 present in test tube is consumed. The CO 2 produced due to respiration is absorbed by KOH present in test tube. Hence, a space is developed due to the consumption of oxygen and hence, the water (coloured) rises in the tubing 1.

(c) In test tube Y, the boiled peas soaked in disinfectant are kept, because the boiled seeds are dead, they cannot respire. Therefore, no process of respiration take place in test tube Y.

(d) Respiration is the cause of the above rise.

(e) The catabolic process of releasing energy from simple sugar for carrying out life processes is called respiration.

(b) Soda lime is kept in bottle ‘A’ so as to check the (presence of) passage of CO 2 present in bottle ‘B’. Because the soda lime has a tendency to absorb CO 2 present in air. The lime water present in the bottle ‘B’ shows that no CO 2 is entering in bottle C with the air passing through bottle ‘C’.

(c) The bottle ‘D’ having lime water will show that CO 2 is produced due to respiration take place in bottle ‘C’ having germinating seeds in it. Due to the CO 2 produced in bottle C the lime water turn milky which it passes through bottle ‘D’.

(d)C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O + (Energy) 38ATP

(e) The bottle ‘C’, when is covered with black cloth, there will be no scope of photosynthesis. Hence, the process of respiration can only be observed.

(f) By introducing a thermometer in bottle ‘C’, the change in temperature is checked or observed. If respiration take place, there will be rise in temperature and if there is no rise in temperature, no respiration occurs. Therefore, a threeholed rubber stopper and a thermometer were introduced.

ICSE Class 9 Biology Solutions

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Describe one experiment you would perform to demonstrate the phenomena that the germinating seeds produce heat.

Plants respiration.

Aim — Experiment demonstrating the fact that germinating seeds produce heat.

Procedure —

• Name two thermo flasks as 'A' and 'B', keep them aside
• Take about 30g of pea or beans seeds and soak them in water for more than 24 hours.
• Split the seeds into two equal groups approximately
• One group of seeds are killed by boiling them and washing them with dilute formaline in order to restrict bacterial decay
• The live germinating seeds need to be placed in flask A and the boiled/killed seeds in flask B.
• Introduce a thermometer into each of the flasks and seal their mouths with cotton wool.
• Take note of the initial reading observed in the thermometer.

Inference —

• A few hours later, thermometer in the flask A shows a higher reading depicting that the seeds that germinate generate heat.
• Flask B shows no rise in the temperature.

Answered By

Related Questions

Describe one experiment you would perform to demonstrate the phenomena that the germinating seeds can respire even in total absence of air., explain why respiration is said to be the reverse of photosynthesis., describe one experiment you would perform to demonstrate the phenomena that the germinating seeds give out carbon dioxide., what is respiration how are respiration and burning similar and how are they different.

How can you show experimentally that heat is liberated during respiration in germinating seeds?

There are two flasks which are filled with germinating seeds and boiled seeds. there are thermometers placed in each flask. the mouth of the flask is covered with wet cotton to prevent inlet of air, prevent contamination of the seeds and to supply water for the process of germination. the germinating seeds can respire by using the water. when there is an increase in the respiration process, the breakdown of the glucose molecule occurs which results in the evolution of energy in the form of heat. due to the heat, there is an increase in temperature which is recorded by the increase in the level of mercury in the thermometer. the temperature rises at a faster rate as compared to the boiled seeds which are not respiring. this proves heat is evolved during the process of germination..

Practical: Conditions for Germination ( Edexcel IGCSE Biology )

Revision note.

Biology Lead

Practical: Conditions for Germination

• Germination is the start of growth in the seed
• Water - allows the seed to swell up , which causes the seed coat (testa) to burst , allowing the growing embryo plant to exit the seed. Water also allows the enzymes in the embryo to start working so that growth can occur ( increases metabolic activity )
• Oxygen - required for respiration , so that energy can be released for germination
• Warmth - germination improves as temperature rises (up to a certain point) as the reactions which take place are controlled by enzymes , which cannot function effectively when temperatures are too low
• As carbon dioxide is not necessary for germination but also does not inhibit it, it makes no difference whether it is present or not
• Test tube holder
• Cress seeds
• Cotton wool
• Set up 4 test tubes, with each containing 10 cress seeds on cotton wool
• For test tube A, leave the cotton wool dry
• For test tube B, add enough water to the cotton wool so that it becomes moist
• For test tube C, add enough water to cover the cotton wool and seeds, then carefully add a layer of oil on top of the water
• For test tube D, add enough water to the cotton wool so that it becomes moist
• Leave tubes A, B and C at room temperature or incubated at a specific temperature (e.g. 20°C)
• Place tube D in a fridge (approximately 4°C)
• Ensure the cotton wool in tubes B and D remains moist throughout this time by adding more drops of water if required
• Compare the results and see which tube has the greatest number of germinated seeds

Conditions required for germination: how to set up the experiment

Results and Analysis

• In test tube A, water is removed
• Test tube B is the control tube, where all factors are present
• In test tube C, oxygen is removed (oxygen cannot pass through the oil and water layers on top of the seeds)
• In test tube D, warmth is removed
• As germination cannot occur if the conditions are not right (i.e. if even one of the three factors required is absent), it would be expected that only the seeds in the control tube will germinate  

Conditions Required for Germination: Example Results Table

Applying CORMS to practical work

• When working with practical investigations, remember to consider your CORMS evaluation

CORMS evaluation

• C - We are changing the abiotic conditions in which the seeds are germinating
• O - The cress seeds will all be taken from the same parent plant (or at least from the same species of cress plant)
• R - We will repeat the investigation several times to ensure our results are reliable
• M1 - We will record how many seeds in each test tube germinate
• M2 - ...after a set time period (e.g. 3 days)
• S - We will control the temperature for tubes A, B and C. We will also control the type of water used (i.e. sterile water, which is made by first boiling then cooling water)

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Seeds are gifts from nature, one organic producer says. It’s ending sales and giving them away

The founders of Fruition Seeds, Matthew Goldfarb, left, and Petra Page-Mann, walk on their farm in Naples, N.Y., on Thursday, Aug. 1, 2024. The multimillion-dollar organic seed company has declared that “seeds are gifts” and will be giving them away after this month. (AP Photo/Cara Anna)

A sign at Fruition Seeds announces the farm in Naples, N.Y., is closed on Thursday, Aug. 1, 2024. The multimillion-dollar organic seed company has declared that “seeds are gifts” and will be giving them away after this month. (AP Photo/Cara Anna)

Fruition Seeds founder Petra Page-Mann holds one of the company’s hundreds of seed varieties offered on Thursday, Aug. 1, 2024. The multimillion-dollar organic seed company has declared that “seeds are gifts” and will be giving them away after this month. (AP Photo/Cara Anna)

A greenhouse shows past work with the garlic harvest at Fruition Seeds in Naples, N.Y., on Thursday, Aug. 1, 2024. The multimillion-dollar organic seed company has declared that “seeds are gifts” and will be giving them away after this month. (AP Photo/Cara Anna)

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NAPLES, New York (AP) — An organic seed company with national reach has surprised its supporters by announcing it will end sales and give hundreds of varieties away, declaring “we can no longer commodify our beloved kin, these seeds, or ourselves.”

The Cocozelle zucchini, now $14.25 per 100 seeds? No charge. Catnip, kale, the rampant mint? All free.

Petra Page-Mann and Matthew Goldfarb, the couple who run Fruition Seeds in upstate New York, said they’re letting go workers, stopping sales on Aug. 27 and relying on public goodwill — donations of money, talent and effort — to grow and distribute seeds on a $76,000 budget.

That’s a dramatic shift for a company with a budget of over $1 million in 2022 and a profile high enough that it’s among a handful of seed companies featured in the New York Botanical Garden’s shop.

“The call is simple enough: Seeds are gifts. Gifts are shared,” the couple said in a long and searching announcement weeks ago. They’ve thought about barriers to access and what they call the indignity of the dollar. Burnout, too, played a role. “We’re weaving a new fabric together, Friends.”

As ripe apples plunked into the grass at their farm in the hilly Finger Lakes region, and workers pounded together a bunkhouse for the volunteers who’ll now be crucial, Page-Mann and Goldfarb were open about not having all the answers.

Their parents are “terrified,” said Goldfarb, 48. “I’m concerned you’re freeloading, I’m concerned you’re gonna become a liability to this community,” he recalled friends and family saying. “And I think the potentially hard thing for people to hear is, yes, that’s actually how this is gonna work.” In a way.

Next year, instead of shipping seed packets, they plan to give away seeds by hosting events and visiting cities around the Northeast. It’s a radical extension of their work with seed libraries, seed swaps and community harvests.

The move has inspired some and bewildered others in their green village of Naples, where cyclists zip past produce stands and Black Lives Matter signs. Elsewhere, some customers have said they’re too far away to get Fruition’s seeds without shipping and will look to other sources.

The announcement noted Fruition’s decision during the COVID-19 pandemic to face painful economic losses and make their online growing courses, featuring the exuberant Page-Mann, 40, free for all. There was joy in giving.

Now they hope others feel the same. They have begun listing their own needs, from financial donations and legal expertise to items like printer paper and Mason jars. “I trust, like air, what is present – though not yet visible – will carry us all,” Page-Mann wrote.

The Fruition founders said they were inspired in part by friend and mentor Adam Wilson, who runs a farm in Keeseville, New York, that he describes as an “experiment in neighborly farming and feeding,” with all food and events offered as gifts.

“And he’s still alive,” Goldfarb said.

But Fruition has been a much larger endeavor, partnering with nearby Cornell University and a number of growers in the region and as far away as Oregon and Idaho.

“They embark on an agri/cultural experiment many times the scale of the work here,” Wilson wrote after the announcement. “I am shaking with excitement, but also a tinge of responsibility.”

Already, Cornell has told Fruition that some of the seed varieties they had agreements for must be returned to Cornell or destroyed, Goldfarb told supporters last month. Conversations with the university continue.

(AP Photo/Cara Anna)

Goldfarb and Page-Mann aren’t saying others should stop selling seeds. They’re looking into forming a nonprofit. They admire the collective work of the not-too-far-away Amish and Mennonite communities. But there is no definite plan.

“We’ll have different answers tomorrow. I hope,” Goldfarb said.

About 40% of the seeds that Fruition has sold have been produced by partners. One of them, Daniel Brisebois with Tourne-Sol farm in Canada, said he was excited to see what would happen now. Others didn’t respond.

Page-Mann and Goldfarb said the most excruciating part of their decision was taking it without the collective consent of their 12 employees.

“Simultaneously they were very gracious, like, ‘This makes sense for you and your lives,’ and also, ‘This sucks,’” Page-Mann said.

One worker told the AP that while they respect where Fruition’s founders are coming from, “so far this transition feels like a big missed opportunity to learn how to minimize harm in the process of trying to transform systems, especially harm toward workers.” The worker, who is looking for new work, spoke on condition of anonymity.

At the bunkhouse under construction on the Fruition farm, local mushroom producer David Colle, 49, said the thinking behind the transformation — a purpose bigger than the individual -- drew him to help build.

Some in the community have said, “I won’t do business with these people anymore,” Colle said, but “you have to have people willing to explore the edges to learn what’s possible.” He’s as curious about Fruition’s future as anyone. He’s given away mushrooms but doesn’t see how to do it full time and still pay the bills.

And he wasn’t completely volunteering his time. “I need money,” he said, sweating in the afternoon heat, and acknowledged: “We’re all walking paradoxes.”