Tag: importance of light for photosynthesis

Questions Related to importance of light for photosynthesis

Moll's half - leaf experiment proves that _________ is essential for photosynthesis to take place. 
biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. chlorophyll

  2. $CO _{2} $

  3. light

  4. $H _{2} O $

Show answer
Correct Option: B
Explanation:

In Moll's half leaf experiment a destarched plant is used.Half part of one of the leaves from the plant is inserted into a corked bottle containing either KOH solution or KOH palletes. The plant is then placed in sunlight for a few hours. The leaf is then tested for starch with iodine solution. Part of the leaf that was inserted in the bottle does not turn blue or test positive for starch. This is because $CO _2$ present in the bottle was aborbed by KOH and the bottle was corked to prevent any entry of air.Proving that $CO _2$ is essential for photosynthesis.

So, the correct answer is $CO _2$


Choose the correct answer from the alternatives given.
Molls experiment demonstrates the necessity of which of the following in photosynthesis

biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. water

  2. oxygen

  3. carbon dioxide

  4. chlorophyll

Show answer
Correct Option: C
Explanation:

Molls experiment evidently shows that plants do not form starch when carbon dioxide is not at their disposal, all the carbon dioxide contained in the bottle having been absorbed by the caustic potash solution.

Thus, the correct answer is 'Carbon dioxide.'

Photochemical phase does not include 
biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. light absorption

  2. water splitting and $ O _{2}$ release

  3. ATP and NADPH formation

  4. $CO _{2}$ fixation

Show answer
Correct Option: D
Explanation:

The complete process of photosynthesis is studied under two phases - photochemical phase and biosynthetic phase. Photochemical phase involves absorption of light energy, photolysis of water with the release of $O _{2}$ and production of assimilatory power (i.e. ATP + NADPH).$CO _{2} $ fixation occurs during biosynthetic phase of photosynthesis. 

In the experiment " To show that $CO _{2}$ is given out during respiration" the water level in the bent tube rise after sometime because

biology nutrition and respiration importance of light for photosynthesis various experiments on photosynthesis experiments on photosynthesis - gases

  1. germinating seeds consume all the $O _{2}$ and $CO _{2}$ in the flask.

  2. the germinating seeds consume $O _{2}$ and give out $CO _{2}$ which is absorbed by a chemical filled in the small test tube.

  3. $CO _{2}$ is given out by the germinating seeds.

  4. seeds need water for germination and grow.

Show answer
Correct Option: B