Chapter 3 Diffusion & Osmosis - Worksheet

Jurongville Secondary School Secondary 3 Express Supplementary Worksheet Syllabus 5100 Name: _________________________ (

)

Class: Sec 3___ Chapter 3: 1.

2.

3.

Date: ____________

Movement of Substances

Name the process by which plants get

a. Mineral salts

Active Transport [1]

b. Water

Osmosis [1]

c. Carbon Dioxide

Diffusion [1]

Which of the processes in Q1

a. Occurs across a partially-permeable membrane

Osmosis [1]

b. Is applicable to movement of solute only

Diffusion [1]

c. Requires cellular respiration

Active transport [1]

Read the statements A to F below and answer the following questions.

a. Only one statement below is correct. Which one is it?

F [1]

b. The other statements can be corrected by changing just one word. For each incorrect statement, underline the wrong word and write the correct one in the box beside it. [5] Statement A: A cell membrane is like a very fine sieve allowing only water molecules to pass though it. Statement B: Diffusion of water through the cell wall is called osmosis Statement C: Wilting occurs only when less water leaves the cell than enters it Statement D: Diffusion results from the unidirectional movement of particles Statement E: Active cells are small and contain plenty of mitochondria Statement F: As cells grow in size, their metabolic rate usually increases

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4.

An experiment was set up as shown and left for 15 minutes. (Note: Iodine reacts with starch to give a characteristic dark blue colour)

Starch solution

Water coloured with iodine

a. What do you observe at the end of the experiment? [1] The liquid level in the tubing rises + the colour of the liquid turns dark blue [1] b. Give an explanation for these observations. [4] Water enters the visking bag through the selectively permeable membrane from a region of higher water potential in the beaker to a region of lower water potential inside the visking bag [1]; by osmosis [1]; the iodine in the water reacts with the starch inside the visking tubing [1]; resulting in a dark-blue solution forming in side the tubing [1]. 5.

Explain the differences observed between how red blood cells and onion cells behave in water and strong sucrose solution. a. In distilled water [4]: _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________

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b. In strong sucrose solution [4]: _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ 6.

The diagram shows a cross-section of a root hair cell. Indicated on this diagram are four ways whereby molecules can move into or out of the cell. The size of the circle indicates the concentration of the molecule.

C

A

D

B a. Which arrow A, B, C or D represents the

i. Movement of mineral salts? C

[1]

ii. Movement of water?

[1]

B

b. Name both the processes listed in (a), giving reasons [4]. C: Active transport B: Osmosis c. i. If glucose moves from this cell to neighbouring cell, which arrow will best represent this movement? [1] A ii. Name this process. [1] Diffusion

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