Year 8 Science · Unit 1 · Lesson 9
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Two words will not be used.
The is a muscular pump that keeps blood moving. Vessels called carry blood away from the heart. Vessels called carry blood back toward the heart, and they have that stop it flowing backwards. The tiny have walls only one cell thick. The is the transport medium that carries substances to and from every cell.
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. The blood inside your veins is blue.
Correct it:
2. The right ventricle pumps blood out to the whole body.
Correct it:
3. Blood carries useful substances such as oxygen to cells and carries wastes away.
Correct it:
4. The heart’s job is to put oxygen into the blood.
Correct it:
5. The heart has four chambers: two atria and two ventricles.
Correct it:
Read the data
| Vessel | Width of the space inside (mm) | Thickness of the wall (mm) |
|---|---|---|
| Artery (medium-sized) | 4 | 1 |
| Vein (medium-sized) | 5 | 0.5 |
| Capillary | 0.008 | 0.0005 (one cell) |
Source: rounded sizes from biology books; real vessels vary a lot.
1. Which vessel has the thickest wall? Which vessel has the widest space inside?
2. The capillary wall is thousands of times thinner than the artery wall. Explain how this very thin wall suits the job capillaries do.
Scenario: a Year 5 student’s idea
“Blood in your veins is blue. You can see it through your skin. It only goes red when it leaks out and touches the air.”
3. Explain what is wrong with the Year 5 student’s idea. Then describe the trip blood takes from the heart to a fingertip and back, naming the three types of vessel in the right places and saying what colour the blood is on the way out and on the way back.
Fill the gap
heart; arteries; veins; valves; capillaries; blood. Not used: lungs, stomach.
True or false
1. False: blood is always red inside the body; blood in veins is dark red. Veins only look bluish through the skin because of the way light passes through skin. 2. False: the right ventricle pumps blood to the lungs; the left ventricle pumps blood to the body. 3. True. 4. False: the heart pumps blood; the blood picks up oxygen in the lungs. 5. True.
Read the data
1. Thickest wall: the artery (1 mm). Widest space inside: the vein (5 mm). [2 marks]
2. Capillaries are the exchange sites. A wall only one cell thick means substances such as oxygen and nutrients only have a tiny distance to pass through to reach the cells, and wastes can pass back into the blood easily. [2 marks: 1 exchange job, 1 short distance through the wall]
Show What You Know
3. Marking guide: 1 blood is always red inside the body (bright red with oxygen, dark red without); 1 veins look blue because of how light passes through the skin, not because the blood is blue; 1 heart pumps blood out along arteries to the finger; 1 in the capillaries oxygen and nutrients pass into the cells and wastes pass into the blood; 1 blood returns to the heart in veins, dark red because it has given up much of its oxygen. [5 marks]
Common error to watch for: mixing up arteries and veins. Arteries carry blood away from the heart; a quick check is “A for away”.