ScienceAges 13-15

Human body systems & organs

Connect major human organs and systems to digestion, circulation, respiration and coordination. Review suitability for your learners before teaching.

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Age band:Ages 10-12 Ages 13-15

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Worksheet StudioPractice pack · Ages 13-15

Human body systems & organs

Take your time. Show your thinking.

1. Why is dietary fibre (roughage from vegetables, fruits and whole grains) important even though humans cannot digest it: it keeps food moving smoothly through the intestines, or it turns into bone?
Heart · Lungs · Digestive Tract
2. Which mineral is essential for building strong bones and teeth (found in dairy products, leafy greens and small fish): calcium or sodium?
Heart · Lungs · Digestive Tract
3. Which nutrient group is primarily needed for building and repairing body cells and muscle tissue (found in fish, eggs, beans and lentils): proteins or water?
Heart · Lungs · Digestive Tract
4. Which digestive enzyme breaks down fats and oils (lipids) into fatty acids and glycerol: lipase or amylase?
Heart · Lungs · Digestive Tract
5. Which muscular tube carries swallowed food from the mouth down to the stomach by wave-like contractions (peristalsis): the oesophagus (gullet) or the trachea (windpipe)?
Heart · Lungs · Digestive Tract
6. Which nutrient group serves as the body’s primary fuel for cellular respiration (found in rice, bread, pasta and fruit): carbohydrates or minerals?
Heart · Lungs · Digestive Tract
7. Which microscopic blood vessels have walls only one cell thick to allow rapid exchange of oxygen, nutrients and waste with body tissues: capillaries or arteries?
Heart · Lungs · Digestive Tract
8. In the human circulatory system, which blood vessels carry blood AWAY from the heart under high pressure with thick muscular walls: arteries or veins?
Heart · Lungs · Digestive Tract
9. Which vitamin found in citrus fruits and fresh vegetables prevents scurvy and supports healthy connective tissue: Vitamin C or Vitamin D?
Heart · Lungs · Digestive Tract
10. Why does the human stomach produce hydrochloric acid: to kill harmful bacteria and provide the acidic pH for pepsin (protease) enzymes, or to digest bones into gold?
Heart · Lungs · Digestive Tract
11. Which dome-shaped muscle beneath the lungs contracts and flattens when you inhale, increasing chest volume and drawing air in: the diaphragm or the bicep?
Heart · Lungs · Digestive Tract
12. What is the main function of the large intestine (colon): to absorb remaining water from undigested food waste, or to pump blood?
Heart · Lungs · Digestive Tract

12 questions · Seed 104741 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 13-15

Human body systems & organs

Answers and reasoning. Review before teaching.

1. Why is dietary fibre (roughage from vegetables, fruits and whole grains) important even though humans cannot digest it: it keeps food moving smoothly through the intestines, or it turns into bone?
It keeps food moving smoothly through the intestines
Fibre adds bulk to aid peristalsis and prevent constipation.
2. Which mineral is essential for building strong bones and teeth (found in dairy products, leafy greens and small fish): calcium or sodium?
Calcium
Calcium phosphate gives bones and tooth enamel their hardness and strength.
3. Which nutrient group is primarily needed for building and repairing body cells and muscle tissue (found in fish, eggs, beans and lentils): proteins or water?
Proteins
Proteins supply amino acids for growth and tissue repair.
4. Which digestive enzyme breaks down fats and oils (lipids) into fatty acids and glycerol: lipase or amylase?
Lipase
Lipase enzymes digest lipids into fatty acids and glycerol.
5. Which muscular tube carries swallowed food from the mouth down to the stomach by wave-like contractions (peristalsis): the oesophagus (gullet) or the trachea (windpipe)?
Oesophagus (gullet)
Peristalsis in the oesophagus pushes the food bolus into the stomach.
6. Which nutrient group serves as the body’s primary fuel for cellular respiration (found in rice, bread, pasta and fruit): carbohydrates or minerals?
Carbohydrates
Carbohydrates are broken down into glucose, the main fuel for cellular respiration.
7. Which microscopic blood vessels have walls only one cell thick to allow rapid exchange of oxygen, nutrients and waste with body tissues: capillaries or arteries?
Capillaries
Thin capillary walls provide a short diffusion pathway between blood and cells.
8. In the human circulatory system, which blood vessels carry blood AWAY from the heart under high pressure with thick muscular walls: arteries or veins?
Arteries
Arteries have thick elastic and muscular walls to withstand high-pressure blood pumped from the heart.
9. Which vitamin found in citrus fruits and fresh vegetables prevents scurvy and supports healthy connective tissue: Vitamin C or Vitamin D?
Vitamin C
Vitamin C (ascorbic acid) is essential for collagen synthesis and immune health.
10. Why does the human stomach produce hydrochloric acid: to kill harmful bacteria and provide the acidic pH for pepsin (protease) enzymes, or to digest bones into gold?
To kill harmful bacteria and provide the acidic pH for pepsin (protease) enzymes
Stomach acid (pH ≈ 1.5–2) destroys pathogens and activates protease enzymes.
11. Which dome-shaped muscle beneath the lungs contracts and flattens when you inhale, increasing chest volume and drawing air in: the diaphragm or the bicep?
Diaphragm
Contraction of the diaphragm and intercostal muscles expands the thorax, lowering pressure so air flows into the lungs.
12. What is the main function of the large intestine (colon): to absorb remaining water from undigested food waste, or to pump blood?
To absorb remaining water from undigested food waste
The large intestine reabsorbs water and electrolytes, leaving semi-solid faeces.

12 questions · Seed 104741 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

Human body systems & organs

Take your time. Show your thinking.

1. Why is dietary fibre (roughage from vegetables, fruits and whole grains) important even though humans cannot digest it: it keeps food moving smoothly through the intestines, or it turns into bone?
Heart · Lungs · Digestive Tract
2. Which mineral is essential for building strong bones and teeth (found in dairy products, leafy greens and small fish): calcium or sodium?
Heart · Lungs · Digestive Tract
3. Which nutrient group is primarily needed for building and repairing body cells and muscle tissue (found in fish, eggs, beans and lentils): proteins or water?
Heart · Lungs · Digestive Tract
4. Which digestive enzyme breaks down fats and oils (lipids) into fatty acids and glycerol: lipase or amylase?
Heart · Lungs · Digestive Tract
5. Which muscular tube carries swallowed food from the mouth down to the stomach by wave-like contractions (peristalsis): the oesophagus (gullet) or the trachea (windpipe)?
Heart · Lungs · Digestive Tract
6. Which nutrient group serves as the body’s primary fuel for cellular respiration (found in rice, bread, pasta and fruit): carbohydrates or minerals?
Heart · Lungs · Digestive Tract
7. Which microscopic blood vessels have walls only one cell thick to allow rapid exchange of oxygen, nutrients and waste with body tissues: capillaries or arteries?
Heart · Lungs · Digestive Tract
8. In the human circulatory system, which blood vessels carry blood AWAY from the heart under high pressure with thick muscular walls: arteries or veins?
Heart · Lungs · Digestive Tract
9. Which vitamin found in citrus fruits and fresh vegetables prevents scurvy and supports healthy connective tissue: Vitamin C or Vitamin D?
Heart · Lungs · Digestive Tract
10. Why does the human stomach produce hydrochloric acid: to kill harmful bacteria and provide the acidic pH for pepsin (protease) enzymes, or to digest bones into gold?
Heart · Lungs · Digestive Tract
11. Which dome-shaped muscle beneath the lungs contracts and flattens when you inhale, increasing chest volume and drawing air in: the diaphragm or the bicep?
Heart · Lungs · Digestive Tract
12. What is the main function of the large intestine (colon): to absorb remaining water from undigested food waste, or to pump blood?
Heart · Lungs · Digestive Tract

12 questions · Seed 104741 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

Human body systems & organs

Answers and reasoning. Review before teaching.

1. Why is dietary fibre (roughage from vegetables, fruits and whole grains) important even though humans cannot digest it: it keeps food moving smoothly through the intestines, or it turns into bone?
It keeps food moving smoothly through the intestines
Fibre adds bulk to aid peristalsis and prevent constipation.
2. Which mineral is essential for building strong bones and teeth (found in dairy products, leafy greens and small fish): calcium or sodium?
Calcium
Calcium phosphate gives bones and tooth enamel their hardness and strength.
3. Which nutrient group is primarily needed for building and repairing body cells and muscle tissue (found in fish, eggs, beans and lentils): proteins or water?
Proteins
Proteins supply amino acids for growth and tissue repair.
4. Which digestive enzyme breaks down fats and oils (lipids) into fatty acids and glycerol: lipase or amylase?
Lipase
Lipase enzymes digest lipids into fatty acids and glycerol.
5. Which muscular tube carries swallowed food from the mouth down to the stomach by wave-like contractions (peristalsis): the oesophagus (gullet) or the trachea (windpipe)?
Oesophagus (gullet)
Peristalsis in the oesophagus pushes the food bolus into the stomach.
6. Which nutrient group serves as the body’s primary fuel for cellular respiration (found in rice, bread, pasta and fruit): carbohydrates or minerals?
Carbohydrates
Carbohydrates are broken down into glucose, the main fuel for cellular respiration.
7. Which microscopic blood vessels have walls only one cell thick to allow rapid exchange of oxygen, nutrients and waste with body tissues: capillaries or arteries?
Capillaries
Thin capillary walls provide a short diffusion pathway between blood and cells.
8. In the human circulatory system, which blood vessels carry blood AWAY from the heart under high pressure with thick muscular walls: arteries or veins?
Arteries
Arteries have thick elastic and muscular walls to withstand high-pressure blood pumped from the heart.
9. Which vitamin found in citrus fruits and fresh vegetables prevents scurvy and supports healthy connective tissue: Vitamin C or Vitamin D?
Vitamin C
Vitamin C (ascorbic acid) is essential for collagen synthesis and immune health.
10. Why does the human stomach produce hydrochloric acid: to kill harmful bacteria and provide the acidic pH for pepsin (protease) enzymes, or to digest bones into gold?
To kill harmful bacteria and provide the acidic pH for pepsin (protease) enzymes
Stomach acid (pH ≈ 1.5–2) destroys pathogens and activates protease enzymes.
11. Which dome-shaped muscle beneath the lungs contracts and flattens when you inhale, increasing chest volume and drawing air in: the diaphragm or the bicep?
Diaphragm
Contraction of the diaphragm and intercostal muscles expands the thorax, lowering pressure so air flows into the lungs.
12. What is the main function of the large intestine (colon): to absorb remaining water from undigested food waste, or to pump blood?
To absorb remaining water from undigested food waste
The large intestine reabsorbs water and electrolytes, leaving semi-solid faeces.

12 questions · Seed 104741 · Age guidance, not curriculum certification