ScienceAges 10-12

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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Worksheet StudioPractice pack · Ages 10-12

Human body systems & organs

Take your time. Show your thinking.

1. In which long, folded organ of the digestive system are most digested nutrients absorbed into the bloodstream through tiny finger-like villi: the small intestine or the oesophagus?
Heart · Lungs · Digestive Tract
2. What are the tiny air sacs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out: alveoli or villi?
Heart · Lungs · Digestive Tract
3. 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
4. Which mineral is required to make haemoglobin in red blood cells (so deficiency leads to anaemia): iron or iodine?
Heart · Lungs · Digestive Tract
5. Which organ produces bile (stored in the gallbladder) to neutralise stomach acid and emulsify fats into tiny droplets: the liver or the lungs?
Heart · Lungs · Digestive Tract
6. 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
7. Which digestive enzyme breaks down fats and oils (lipids) into fatty acids and glycerol: lipase or amylase?
Heart · Lungs · Digestive Tract
8. Where does digestion begin in the human body through chewing and the action of salivary amylase: in the mouth or in the large intestine?
Heart · Lungs · Digestive Tract
9. 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
10. Which blood vessels carry blood BACK toward the heart and contain valves to prevent backflow: veins or arteries?
Heart · Lungs · Digestive Tract
11. Which digestive enzyme breaks down large starch molecules into simple sugars: amylase or lipase?
Heart · Lungs · Digestive Tract
12. 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

12 questions · Seed 104736 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 10-12

Human body systems & organs

Answers and reasoning. Review before teaching.

1. In which long, folded organ of the digestive system are most digested nutrients absorbed into the bloodstream through tiny finger-like villi: the small intestine or the oesophagus?
Small intestine
Villi and microvilli in the small intestine provide a huge surface area for nutrient absorption.
2. What are the tiny air sacs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out: alveoli or villi?
Alveoli
Millions of alveoli in the lungs provide a large moist surface area surrounded by capillaries for gas exchange.
3. 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.
4. Which mineral is required to make haemoglobin in red blood cells (so deficiency leads to anaemia): iron or iodine?
Iron
Iron sits at the core of the haem group in haemoglobin that binds oxygen.
5. Which organ produces bile (stored in the gallbladder) to neutralise stomach acid and emulsify fats into tiny droplets: the liver or the lungs?
Liver
The liver secretes alkaline bile, which emulsifies lipids to increase surface area for lipase enzymes.
6. 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.
7. 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.
8. Where does digestion begin in the human body through chewing and the action of salivary amylase: in the mouth or in the large intestine?
In the mouth
Teeth mechanically break down food while saliva begins digesting starch into maltose.
9. 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.
10. Which blood vessels carry blood BACK toward the heart and contain valves to prevent backflow: veins or arteries?
Veins
Veins operate at lower pressure and use one-way valves to keep blood flowing toward the heart.
11. Which digestive enzyme breaks down large starch molecules into simple sugars: amylase or lipase?
Amylase
Carbohydrases such as amylase catalyse the breakdown of starch into sugars.
12. 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.

12 questions · Seed 104736 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 10-12

Human body systems & organs

Take your time. Show your thinking.

1. In which long, folded organ of the digestive system are most digested nutrients absorbed into the bloodstream through tiny finger-like villi: the small intestine or the oesophagus?
Heart · Lungs · Digestive Tract
2. What are the tiny air sacs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out: alveoli or villi?
Heart · Lungs · Digestive Tract
3. 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
4. Which mineral is required to make haemoglobin in red blood cells (so deficiency leads to anaemia): iron or iodine?
Heart · Lungs · Digestive Tract
5. Which organ produces bile (stored in the gallbladder) to neutralise stomach acid and emulsify fats into tiny droplets: the liver or the lungs?
Heart · Lungs · Digestive Tract
6. 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
7. Which digestive enzyme breaks down fats and oils (lipids) into fatty acids and glycerol: lipase or amylase?
Heart · Lungs · Digestive Tract
8. Where does digestion begin in the human body through chewing and the action of salivary amylase: in the mouth or in the large intestine?
Heart · Lungs · Digestive Tract
9. 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
10. Which blood vessels carry blood BACK toward the heart and contain valves to prevent backflow: veins or arteries?
Heart · Lungs · Digestive Tract
11. Which digestive enzyme breaks down large starch molecules into simple sugars: amylase or lipase?
Heart · Lungs · Digestive Tract
12. 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

12 questions · Seed 104736 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 10-12

Human body systems & organs

Answers and reasoning. Review before teaching.

1. In which long, folded organ of the digestive system are most digested nutrients absorbed into the bloodstream through tiny finger-like villi: the small intestine or the oesophagus?
Small intestine
Villi and microvilli in the small intestine provide a huge surface area for nutrient absorption.
2. What are the tiny air sacs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses out: alveoli or villi?
Alveoli
Millions of alveoli in the lungs provide a large moist surface area surrounded by capillaries for gas exchange.
3. 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.
4. Which mineral is required to make haemoglobin in red blood cells (so deficiency leads to anaemia): iron or iodine?
Iron
Iron sits at the core of the haem group in haemoglobin that binds oxygen.
5. Which organ produces bile (stored in the gallbladder) to neutralise stomach acid and emulsify fats into tiny droplets: the liver or the lungs?
Liver
The liver secretes alkaline bile, which emulsifies lipids to increase surface area for lipase enzymes.
6. 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.
7. 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.
8. Where does digestion begin in the human body through chewing and the action of salivary amylase: in the mouth or in the large intestine?
In the mouth
Teeth mechanically break down food while saliva begins digesting starch into maltose.
9. 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.
10. Which blood vessels carry blood BACK toward the heart and contain valves to prevent backflow: veins or arteries?
Veins
Veins operate at lower pressure and use one-way valves to keep blood flowing toward the heart.
11. Which digestive enzyme breaks down large starch molecules into simple sugars: amylase or lipase?
Amylase
Carbohydrases such as amylase catalyse the breakdown of starch into sugars.
12. 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.

12 questions · Seed 104736 · Age guidance, not curriculum certification