Q5 of 18 Page 62

Suggested Activities

Put dried raisins (dry grapes) in a dish with water. What is the change in the raisins after some time? Why?

When dried raisins are put in water, they will swell up due to entry of water inside them. As a result of osmosis, raisins absorb water. Since the medium surrounding the raisins has a higher concentration of water, the water molecules move in. The surrounding solution is hypotonic. The water molecules move along the concentration gradient from a region of higher concentration to a region of lower concentration.


SWELLED UP RAISINS


More from this chapter

All 18 →
4

Answer the following questions:

0.9% sodium chloride solution is good and balanced to RBC. A lab technician accidentally places a sample of RBC’s in 1.8% sodium chloride solution. What happens? Why?

 4

Answer the following questions:

Diagrams of two different cells are given below. Which one of the two is a plant cell? Support your answer.



(i) Name the parts 1, 2, 3 and 4.


(ii) Write the functions of 1 and 3.


(iii) Draw a diagram to show the structure of 4 and label the parts.


(iv) Draw a diagram of a plant cell and label the parts.

 5

Suggested Activities

Remove the shell of an egg by dissolving it in dilute hydrochloric acid. A thin outer skin now encloses the egg. Put the egg in water. Observe after a few minutes. What is your inference?

 5

Suggested Activities

Place a similar de-shelled egg in a concentrated salt solution for a few minutes. Observe the changes. Record your observations giving reasons.