Advertisements
Advertisements
Question
Given alongside is the diagram of an experimental set-up:
- What is the objective of this experiment?
- Will it work satisfactorily? Give reason.
- What alteration(s) will you make in it for obtaining expected result?
- Would you take any steps before starting the experiment? Describe this step and explain its necessity.
Solution
- To demonstrate the importance of carbon dioxide in photosynthesis.
- No, the experiment will not work satisfactorily, as the beaker contains lime water and not potassium hydroxide to absorb CO2.
- Place potassium hydroxide in the beaker instead of lime water.
- The plant must be kept in complete darkness for 48 hours in order to destarch its foliage prior to commencing the experiment. The reason for this is that the experiment will yield false results if the plant is not destarched, as the leaf deposited in the beaker may contain starch that was previously stored, even if no starch is produced during the experiment.
APPEARS IN
RELATED QUESTIONS
A healthy oat seeding in a pot is transferred from light to any airy but completely dark room. How would it differ from its original condition in appearance after about a week? Explain the difference.
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 and ______ (3) solution is added. The region which contains starch, turns ______ (4) and the region which does not contain starch, turns ______ (5)
Given alongside is the diagram of an experimental set-up:
Would you take any step before starting the experiment? Describe this step and explain its necessity.
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.
During the starch test, why was the leaf
(1) boiled in water
(2) boiled in methylated spirit
Where are the chlorophyll pigments present in a cell?
Name the following:
The site of light reaction in the cell of a leaf.
Complete the following sentence with appropriate word:
Carbon dioxide enters the leaf through _______.
Choose the Odd One Out
Which of the following is used to remove chlorophyll from the leaves?
Given below is the diagram of an experimental set-up (final stage). Study the same and answer the following questions:
- What is the main aim of the experiment?
- Oxygen gas shown in the experiment is released from which of the raw materials?
- How would you confirm the presence of oxygen gas?
- Name the chemical substance which can be added in water to enhance the process/rate of release of oxygen gas.
- Draw a neat and labelled diagram of the same experiment for its initial stage.
