Biology
Given below is the diagram of an apparatus used to study a particular phenomenon in plants:
(a) Name the apparatus.
(b) What is it used for?
(c) What is the role played by the air-bubble in this experiment?
(d) What is the use of the reservoir?
(e) What happens to the movement of the air-bubble if the apparatus is kept:
- In the dark
- In sunlight
- In front of a fan
Give a reason in each case.
Transpiration
259 Likes
Answer
(a) Name of the apparatus is Ganong's potometer.
(b) Ganong’s potometer is used to measure the rate of water intake by a plant.
(c) The air bubble which was introduced into the horizontal graduated capillary tube moves along as transpiration proceeds. As the water is lost from the twig, a suction force is set up which pulls the water from the beaker and the bubble in the capillary tube moves along.
(d) Reservoir is used to release the water into the capillary tube by opening the stop cock.
(e) The movement of air bubble is affected as follows:
- If the apparatus is kept in the dark, there will be no transpiration as the stomata would be closed. As a result, there would be no movement of the air bubble and it would remain stable.
- During the day, the stomata are open to facilitate the inward diffusion of CO2 for photosynthesis. At night they are closed. Therefore, more transpiration occurs during the day. As a result, the movement of the air bubble would be larger since there would be more loss of water due to transpiration.
- If the apparatus is kept in front of a fan, the rate of transpiration will be more. As a result, the movement of the air bubble would be larger since there would be more loss of water due to transpiration as the velocity of wind/air increases.
Answered By
175 Likes
Related Questions
The given figure represents an experiment:
(a) Leaf A was coated with grease on both the surfaces.
(b) Leaf B was coated with grease on the lower surface.
(c) Leaf C was coated with grease on the upper surface.
(d) Leaf D was left without any application of grease.All the four leaves A, B, C and D were left in a room for about 24 hours.
(i) Which leaf dries first? Give reason.
(ii) Which leaf dries last? Give reason.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.
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.