Biology
An apparatus as shown below was set up to investigate a physiological process in plants. The setup was kept in sunlight for two hours. Droplets of water were then seen inside the bell jar. Answer the questions that follow:
(a) Name the process being studied.
(b) Explain the process named above in (a).
(c) Why was the pot covered with a plastic sheet?
(d) Suggest a suitable control for this experiment.
(e) Mention two ways in which this process is beneficial to plants.
(f) List three adaptations in plants to reduce the above mentioned process.
Answer
(a) Transpiration
(b) Transpiration is a process during which water is lost in the form of water vapour through aerial parts of the plant.
(c) The pot is covered with a plastic sheet to prevent evaporation of water from the soil.
(d) A control for this experiment will be an empty polythene bag with its mouth tied.
(e) Transpiration is beneficial to plants in the following ways:
- It creates a suction force in the stem which enables the roots to absorb water and minerals.
- It helps in cooling the plant in hot weather.
(f) Some plants have developed adaptations to reduce transpiration to cut down loss of water such as:
- Sunken stomata
- Narrow leaves
- Reduced exposed surface by rolling or folding of leaves.
Related Questions
The figure given below represents an 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.
(a) Name the process intended for study.
(b) Define the above mentioned process.
(c) When the weight of the test tubes A and B is taken before and after the experiment, what change is observed? Justify.
(d) What is the purpose of keeping the test tube B in the experimental setup?
(e) What is the purpose of putting oil in the test tube?
Given ahead is the diagram of an experimental set up to study the process of transpiration in plants. Study the same and then answer the questions that follow:
(a) Name the colour of dry cobalt chloride paper.
(b) Is the experimental leaf a monocot or a dicot? Give a reason to support your answer.
(c) Why are glass slides placed over the dry cobalt chloride papers?
(d) After about half an hour what change, if any, would you expect to find in the cobalt chloride paper placed on the dorsal and ventral sides of the leaf? Give a reason to support your answer.
Given below is the figure of a stoma. Study the same and answer the following questions:
(a) Label the guidelines A and B.
(b) Write the exact location of the above mentioned structures.
(c) Mention one important role of structure A.
(d) Write three important roles of structure B.
(e) Redraw the same figure when structures A are in flaccid condition. When does flaccid condition occur ?
An outline sketch of a tree is shown in a diagram below. Study the same and answer the questions that follow:
(a) Name and define the phenomenon labelled A in the diagram.
(b) Write the significance of the process mentioned in A for the plants.
(c) What do the direction of arrows in B and C indicate? Name the phenomenon.
(d) Draw a neat and labelled diagram of an opened stomata.