Test for Sunlight

Q.

The procedure of an experiment is given as: Destarch the given potted plant. Cover a portion of leaf with a strip of black paper and keep it in sunlight for 6 hours. Test the presence of starch in the leaf.

What is the aim of the above experiment?

1. To demonstrate that light is necessary for photosynthesis.

2. To demonstrate starch is formed during photosynthesis.

3. None of the above.

4. To demonstrate photosynthesis can happen even without sunlight.

Q. How is energy stored in ATP used to transport food in plants?

Q.

How does light influence plant life?

Q.

The mechanism by which sugars from leaves are transported through the phloem to growing tissues is called ___.

1. Pressure flow

2. Osmotic flow

3. Diffusion flow

4. Active gradient flow

Q.

Do plants absorb green light?

Q.

Increase in __________ results in the decrease of transpiration.

1. atmospheric pressure

2. carbon dioxide

3. temperature

4. sunlight

Q.

Leaves when treated with iodine give blue-black colour. Give reason.

Q. Two healthy green plants were places in the dark for 24 hours. They were then set up, as shown in the figure, for 4 hours. Then a leaf was taken form each plant and the chlorophyll was removed from the leaves:
(i) What is the next and final step in this experiment?
(ii) What would be the results of the final step?
(iii) Why was it necessary to grease the glass sheet?
(iv) What hypothesis is being tested in this experiment?
Figure

Q. The diagram alongside represents an experiment conducted to prove the importance of a factor in photosynthesis.
Study the same and then answer the questions that follow:
Figure

(i) Name the factor being studied in this experiment.
(ii) Why was the plant kept in a dark room before conducting the experiment?
(iii) Why was the experimental leaf then kept in
1. boiling water

2. methylated spirit?
(iv) Name the solution used to test for the presence of starch in the leaf.
(v) What will we observe in the experimental leaf at the end of the starch test?
(vi) Give a balanced chemical equation to represent the process of photosynthesis.

Q.

What are the connecting substances between light and dark reaction

Q.

Give account of reaction of the photosynthesis reaction ?

Q. Why we should not test for glucose instead of starch in the green leaves?

1. The glucose formed during photosynthesis gets polymerised into starch. So stable product one can test is starch.
2. Both A and B.
3. The glucose formed during photosynthesis gets polymerised into fructose. So starch gives a positive test.
4. None of the above.

Q. A plant was kept in a dark room for a week. When its leaves are tested with iodine solution, it did not show the presence of starch. From this experiment we can conclude that _____ is required for photosynthesis.

1. Sunlight
2. Iodine
3. Starch
4. Darkness

Q. Given in the box are steps written randomly for the experiment to show that light is essential for photosynthesis. Which of the following sequences of steps is to be followed by the successful run of the experiment?

1. (i), (iii), (ii) (iv), (v), (vi)
2. (ii), (i), (v), (vi), (iii), (iv)
3. (iii), (ii), (v), (i), (vi), (iv)
4. (v), (ii), (i), (iii), (iv), (vi)

Q. A potted destarched plant was taken in order to prove that light is necessary for photosynthesis.
(i) What is meant by 'destarched plant'? How can it be destarched?
(ii) Using the destarched plant describe step by step how you would proceed to prove that in the absence of light the leaf cannot manufacture starch.

Q. A plant is kept in a dark cupboard for about 48 hours before conducting any experiment on photysynthesis to

1. Remove starch from the plant.
2. Ensure that starch is not translocated from the leaves.
3. Remove chlorophyll from the leaf of the plant.
4. Remove starch from the experimental leaf.

Q. Explain major events that occur during photosynthesis along with reacti

Q. When the rate of translocation is slow, the rate of photosynthesis shall:

1. Decrease
2. Increase
3. Remain unchanged
4. Become zero

Q. Word dark reaction for biosynthetic phase of photosynthesis is misnomer word because ___________________.

1. Dark reaction occur during dark
2. Dark reaction occur during day
3. Dark reaction is completely free from light
4. Dark reaction occur during short dark intervals

Q. Monika planted two plants in pot A and pot B. She poured the same amount of water into both the pots but she placed pot A out in the open ground.Where sunlight can fall on it and pot B in a dark room where there is no sun light. After some days she observed that the plant in pot A has green leaves and grown in size while the plant in pot B has died, can you tell the reason?

1. The plant in pot A is more stronger
2. Monika poured more water in pot A
3. Plants need light to prepare food
4. None of the above

Q.

Consider the leaf of a plant shown in the figure below:

After destarching the plant, it was partially covered with a lightproof paper (as shown in the figure above), and the entire plant kept in the sunlight for 3-4 hours. After this, the starch test was carried out on the leaf. Which of the following would the leaf appear like at the end of the starch test?

1. a

2. b

3. c

4. none of these

Q. The growth of a plant or a plant part towards or away from light is called .

1. thigmotropism
2. phototropism
3. hydrotropism

Q. An experiment was set up as shown in the adjoining figure. The twig in the diagram was intact on the plant and it was left as such in sunlight for a few hours.
(i) What is the aim of the above experiment?
(ii) Why was potassium hydroxide placed inside the conical flask?
(iii) What test would you perform on the leaf inside the flask?
(iv) What is the expected result of the above test?
(v) Is it necessary to similarly test on outer leaf also? Give a reason.
Figure

Q. Which of the following wavelength of light is absorbed maximum for photosynthesis?

1. Red light
2. Blue light
3. Yellow light
4. Green light

Q.

The teacher instructed a student to place a healthy potted shoe flower plant in a dark room for 24 hours prior to an experiment on photosynthesis. The purpose of placing it in a dark room is

1. To increase the intake of carbon dioxide

2. To destarch the leaves

3. To increase the activity of chloroplast in leaves

4. To denature the enzymes in the leaves

Q. Seedlings grown in dark are

1. Similar to those grown in light.
2. Taller than those grown in light.
3. Shorter than those grown in light.
4. Not able to grow.

Q. Plant -> Destarched -> Part of leaf covered with black paper strip -> Starch test
These steps prove the importance of in photosynthesis.

1. chlorophyll
2. sunlight
3. carbon dioxide
4. oxygen

Q. The figure given below represents experimental set up with a weighing machine to demonstrate a particular process in plants. The experimental set up was placed in bright sunlight. Study the diagram and answer the following questions:
Define the above mentioned process.

Q. What will be the result of the starch test performed on leaf 'A' shown in the diagram? Give an example of a plant with variegated leaves.

Q. The figure given below represents experimental set up with a weighing machine to demonstrate a particular process in plants. The experimental set up was placed in bright sunlight. Study the diagram and answer the following questions:
When the weight of the test tube (A and B) is taken before and after the experiment, what is observed?
Give reasons to justify your observation in A and B.