Year 8 Science · Unit 1 · Lesson 11
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Two words will not be used.
Animals need from food, because their need useful materials to work. Breaking food down into smaller, usable parts is called . The useful materials then move from the gut into the . This step is called .
Put the gut in order
Number the parts from 1 (where food goes in) to 5 (the last part food passes through before the anus).
| Order (1–5) | Part of the gut |
|---|---|
| Stomach | |
| Large intestine | |
| Mouth | |
| Small intestine | |
| Oesophagus |
1. In which part of the gut are most nutrients absorbed into the blood? Name the tiny finger-like structures that give it a very large surface.
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. Chewing is part of digestion, because it breaks food into smaller pieces.
Correct it:
2. Digestion and absorption are two names for the same step.
Correct it:
3. The stomach uses acid and enzymes to break food down.
Correct it:
4. The oesophagus is where most food is broken down.
Correct it:
5. As soon as food reaches the stomach, the cells in your legs can use it.
Correct it:
2. Glucose tablets help a person with low blood sugar feel better within minutes. Glucose is already made of very small particles. Suggest why the glucose gets into the blood faster than the starch in a slice of bread.
A model of chewing
A class used sugar to model what chewing does to food. Each group dropped one sugar cube into 200 mL of room-temperature water, stirred at the same speed and timed how long it took until no sugar could be seen. The cube was whole, cut into four pieces, or crushed into powder.
| Form of the sugar cube | Trial 1 | Trial 2 | Trial 3 | Mean |
|---|---|---|---|---|
| Whole | 96 | 104 | 100 | 100 |
| Cut into four pieces | 61 | 55 | 58 | 58 |
| Crushed into powder | 22 | 18 | 23 |
Source: sample class results.
3. Calculate the mean time for the crushed sugar and write it in Table 1.
Answer s
4. Describe the pattern in Table 1. Then use it to explain why chewing food well helps the rest of digestion.
5. A student writes: “Food goes straight into the body, where cells use it immediately.” Rewrite this as a stronger scientific explanation of how the materials in a sandwich reach a muscle cell in your arm.
Fill the gap
nutrients; cells; digestion; blood; absorption. Not used (2): oxygen, urine.
Put the gut in order
Reading down the table as printed: 3, 5, 1, 4, 2. (Mouth, oesophagus, stomach, small intestine, large intestine.)
1. The small intestine; villi. [2 marks]
True or false
1. True. 2. False: digestion breaks food down; absorption moves useful materials into the blood. 3. True. 4. False: the oesophagus only carries food to the stomach; food is broken down in the mouth and stomach. 5. False: the food must still be digested and absorbed in the small intestine, then carried by the blood to the leg cells.
2. Starch is made of large particles, so it must first be digested (broken down into small sugar particles) before it can be absorbed. Glucose is already small enough, so it can be absorbed in the small intestine straight away. [2 marks: 1 starch must be digested first; 1 glucose already small enough to absorb]
Go Deeper
3. (22 + 18 + 23) ÷ 3 = 63 ÷ 3 = 21 s. [2 marks: 1 working, 1 answer with unit]
4. The smaller the pieces, the faster the sugar dissolved (100 s whole, 58 s in four pieces, 21 s crushed). Chewing breaks food into smaller pieces in the same way, which gives saliva and stomach juices more surface to work on, so chemical digestion is faster. [3 marks: 1 pattern with data; 1 chewing makes smaller pieces; 1 more surface, so faster digestion]
Show What You Know
5. Marking guide (points expected): 1 food does not go straight to cells, because it must be digested and absorbed first; 1 mouth: teeth chew it into small pieces and saliva starts chemical digestion; 1 stomach: acid and enzymes break it down further; 1 small intestine: useful materials are absorbed through the villi into the blood; 1 the blood (circulatory system) carries them to the arm muscle cell. [5 marks]
Common error to watch for: using “digestion” for the whole journey. Digestion only breaks food down; absorption is the separate step where materials cross into the blood.