Advertisements
Advertisements
Question
Explain how soaked seeds swell up and burst their seed coats.
Advertisements
Solution
When soaked in water, the seeds swell up due to imbibition and endosmosis. During these two processes water enters the cell. Due to endosmosis, at some point, the seed coat is unable to bear the turgor pressure and hence, the seed coat bursts.
RELATED QUESTIONS
A candidate in order to study the process of osmosis has taken 3 potato cubes and put them in 3 different beakers containing 3 different solutions. After 24 hours, in the first beaker the potato cube increased in size, in the second beaker the potato cube decreased in size and in the third beaker there was no change in the size of the potato cube. The following diagram shows the result of the same experiment:
(i) Give the technical terms of the solutions used in beakers, 1, 2 and 3.
(ii) In beaker 3, the size of the potato cube remains the same. Explain the reason in brief.
(iii) Write the specific feature of the cell sap of root hairs which helps in absorption of water.
(iv) What is osmosis?
(v) How does a cell wall and a cell membrane differ in their permeability?
Define the following:
Hypertonic solution
A leaf cell of a water plant was placed in a liquid other than pond water. After sometime, it assumed a shape as shown below:
Redraw in the space provided, the diagram of the cell if it is soon placed in ordinary water for some time.
What do you mean by transpiration pull ?
Give Reasons for the following.
Plants begin to die when the excess of soluble fertilizers are added to the soil?
In an experiment, two sets of apparatus were set up as shown below:
In A there is a concentrated sugar solution inside the thistle funnel and red ink in the water outside the funnel. In B there is a concentrated glucose solution with red ink inside the thistle funnel and water outside the thistle funnel.
In both A and B the level of liquid inside the funnels rises up the tubes. In A the sugar solution turns red and in B, the water turns red.
Study the given observations and answer these questions:
- Name the process by which red ink moves in A and B.
- Which type of pressure forces the water molecules to move towards thistle funnels and cause a rise in the water level?
- Where does this process occur in plants and animals?
- What material could be used as a semi-permeable membrane?
Multiple Choice Question:
Marine fish when thrown under tap water bursts because of:
The given statement is incorrect. Rewrite the correct statement:
Fresh water fish when placed in hypertonic salt solution absorb water and burst.
