(a) Name the physiological process that releases the bubbles of oxygen.(b) Explain the physiological process as mentioned above in (a).(c) What is the purpose of keeping a snail in test-tube...
8. A potted plant was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours. One of the leaves was covered with black paper in the centre. The potted plant was then placed in sunlight for a few hours.
(a) What aspect of photosynthesis was being tested? (b) Why was the plant placed in the dark before beginning the experiment? (c) During the starch test, why was the leaf (1) boiled in...
7. Draw a neat diagram of the stomatal apparatus found in the epidermis of leaves and label the Stoma, Guard cells, Chloroplast, Epidermal cells, Cell wall and Nucleus.
Solution – diagram showing stomatal apparatus :
6. Given below is the diagram of an experimental set-up
(a) What is objective of this experiment? (b) Will it work satisfactorily? Give reason. (c) What alteration(s) will you make in it for obtaining expected result? (d) Would you take any step before...
5. Enumerate the steps involved in testing a green leaf for the presence of starch.
Solution : the steps are – Dipping of the leaf in boiling water to kill the cellsTo remove chlorophyll boil the leaf in methylated spirit . the leaf becomes hard and brittle To soften it place it...
3.Given below is a schematic diagram to illustrate some aspects of photosynthesis.
(a) Fill up the gaps, in blank spaces (1-4), by writing the names of the correct items.(b) What phenomenon do the think arrows A and B indicate respectively Solution – The gaps are as follows:...
2. Photosynthesis in green plants is directly and indirectly dependent on so many plant structures. Explain briefly the role of the following structures in this process.
(a) Guard cells(b) Cuticle(c) Mesophyll cells(d) Xylem tissue in the leaf veins(e) Phloem tissue in Leaf Veins(f) Stomata Solution - Guard cells – regulate the rate of transpiration by opening and...
16. Complete the following by filling the blanks 1 to 5 with appropriate words/ terms/ phrases:
To test the leaf for starch, the leaf is boiled in water to (1) ……………. It is next boiled in methylated spirit to (2) ……………. The leaf is placed in warm water to soften it. It is then placed in a dish...
15. All life owes its existence to chlorophyll. Give reason.
Solution – Chlorophyll is the green colouring matter found in plants . These are minute oval bodies bounded by a double membrane . Chlorophyll is the key element in the process of the photosynthesis...
14. How do non-green plants such as fungi and bacteria obtain their nourishment?
Solution : non green plants such as fungi and bacteria get their nourishment from decaying organic matter in the environment . Fungi and bacteria are decomposers that feed on dead and decayed...
13. Complete the following food chains by writing the names of appropriate organisms in the blanks:
(i) Grass → ………… Snake →…………… (ii)……….. → Mouse …………… → Peacock Solution : ( i ) Grass → ………… Snake →…………… Grass → rat → Snake → hawk (...
12. Describe the main chemical changes which occur during photosynthesis in:(i) Light reaction
(ii) Dark reaction
Solution : ( i ) light reaction –light plays a key role in light reaction . The phase is called as photochemical phase . The two steps in light reaction are : Step 1 – the chlorophyll is activated...
11. How would you demonstrate that green plants release oxygen when exposed to light?
Solution : experiment to show that oxygen is released when plants are exposed to light Take a beaker containing pond water and place few aquatic plants in it covered by stemmed funnel .A test tube...
10. Most leaves have the upper surface more green and shiny than the lower one. Why?
Solution : the upper surface of most of the leaves is more green and shiny than the lower one .This is because of more concentration of the chloroplasts and stomata in the upper layer . This helps...
9. Why is it not possible to demonstrate respiration in a green plant kept in sunlight?
Solution – in day time the plants undergo photosynthesis so it is not possible to show respiration in green plants at that time . Photosynthesis takes place in the day time and requires carbon...
8. Why is it necessary to place a plant in the dark before starting an experiment on photosynthesis? Explain
Solution : the plant used for the experiment of the photosynthesis is placed in the dark in starting so as to remove the starch from the leaves . The plant is placed in the dark for 24 – 48 hours so...
7. “Oxygen is a waste product of photosynthesis.” Comment.
Solution : photosynthesis is the only process which liberates oxygen in the environment . Life cant be imagined by the oxygen . All living organisms need oxygen to survive , It is the life line ....
6. State any four differences between photosynthesis and respiration.
Solution : difference between photosynthesis and respiration are – PhotosynthesisRespirationTakes place only in green plants and in photosynthetic bacteriaRespiration occurs in all living...
5. Given below are five terms. Rewrite the terms in the correct order so as to be in logical sequence with regard to photosynthesis: (i) water molecules, (ii) oxygen, (iii) grana, (iv) hydrogen and hydroxyl ions, (v) photons.
Solution : the correct order of the terms with regard to photosynthesis will be – (v) photons, (iii) grana, (i) water molecules, (iv) hydrogen and hydroxyl ions, (ii) oxygen
4. Are the following statements true or false? Give reason in support of your answer.
(a) The rate of photosynthesis continues to rise as long as the intensity of light rises. (b) The outside atmospheric temperature has no effect on the rate of photosynthesis. (c) If you immerse a...
3. Fill in the blanks with the appropriate answer from the choices given in the brackets.
(a) The site of light reaction in the cells of a leaf is……………… (cytoplasm, stroma, grana).(b) The chemical substance used to test the presence of starch in the cell of a leaf is…………… (CaCl2, iodine...
2. Identify the false statements and rewrite them correctly by changing the first or last word only. (a) Dark reaction of photosynthesis occurs during night time.
(b) Immediate product of photosynthesis is glucose. (c) Starch produced in a leaf remains stored in it...
1. Mention one difference between the following on the basis of what is given in brackets.(a) Respiration and photosynthesis (gas released)
(b) Light and dark reactions (products formed) (c) Producers and consumers (mode of nutrition) (d) Grass and grasshopper (mode of nutrition) (e) Chlorophyll and chloroplast (part of plant cell)...
1. Name the following:
(a) The category of organisms that prepare their own food from basic raw materials. (b) The kind of plastids found in the mesophyll cells of the leaf. (c) The compound which stores energy in the...
9. During photosynthesis, the oxygen in glucose comes from
a) CO2 b) water c) both CO2 and water d) oxygen via air correct option – ( a ) explanation – carbon dioxide provides the oxygen in glucose during the process of photosynthesis .
8. A plant is kept in a dark cupboard for 48 hours before conducting any experiment on photosynthesis in order to
a) remove chlorophyll from leaves b) remove starch from the leaves c) ensure that no photosynthesis occurred d) ensure that the leaves are free from starch correct option – ( d ) explanation –...
7. The specific function of light energy in the process of photosynthesis is to
a) reduce carbon dioxide b) synthesise glucose c) activate chlorophyll d) split water molecule correct option – ( c ) explanation – the chlorophyll is activated by the light energy in the process of...
6. Which one chemical reaction occurs during photosynthesis?
a) Carbon dioxide is reduced and water is oxidised b) Water is reduced and carbon dioxide is oxidised c) Both carbon dioxide and water are oxidised d) Both carbon dioxide and water are reduced...
5. If the rate of respiration becomes more than the rate of photosynthesis, plants will:
a) continue to live, but will not be able to store food b) be killed instantly c) grow more vigorously because more energy will be available d) stop growing and die gradually of starvation correct...
4. Chlorophyll in a leaf is required for
a) breaking down water into hydrogen and oxygen b) emitting green light c) trapping light energy d) storing starch in the leaves correct option – ( c ) explanation – chlorophyll in a leaf is...
3. The rate of photosynthesis is not affected by
a) light intensity b) humidity c) temperature d) CO2 concentration correct option – ( b ) explanation - humidity does not affects the rate of photosynthesis
2. The number of water molecules required in the chemical reactions to produce one molecule of glucose during photosynthesis is
a) six b) twelve c) eighteen d) twenty-four correct option – ( b ) explanation -twelve water molecules are required in the chemical reaction of photosynthesis to produce one molecule of glucose...
1. The production of starch, and not glucose, is often used as a measure of photosynthesis in leaves because
a) starch is immediate product of photosynthesis b) glucose formed in photosynthesis soon gets converted into starch c) starch is soluble in water d) sugar cannot be used correct option – ( b )...