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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Worksheet StudioPractice pack · Ages 13-15

Human body systems & organs

Take your time. Show your thinking.

1. Which blood vessels carry blood BACK toward the heart and contain valves to prevent backflow: veins or arteries?
Heart · Lungs · Digestive Tract
2. Which component of human blood contains haemoglobin and transports oxygen from the lungs to body tissues: red blood cells or platelets?
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 tiny cell fragments in blood help form clots at a wound to stop bleeding: platelets or red blood cells?
Heart · Lungs · Digestive Tract
5. 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
6. 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
7. 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
8. 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
9. 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
10. 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
11. Which digestive enzyme breaks down large starch molecules into simple sugars: amylase or lipase?
Heart · Lungs · Digestive Tract
12. 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

12 questions · Seed 47 · 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. 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.
2. Which component of human blood contains haemoglobin and transports oxygen from the lungs to body tissues: red blood cells or platelets?
Red blood cells
Red blood cells (erythrocytes) are packed with haemoglobin and lack a nucleus to maximise oxygen transport.
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 tiny cell fragments in blood help form clots at a wound to stop bleeding: platelets or red blood cells?
Platelets
Platelets trigger blood clotting to seal damaged vessels.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
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. 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.

12 questions · Seed 47 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

Human body systems & organs

Take your time. Show your thinking.

1. Which blood vessels carry blood BACK toward the heart and contain valves to prevent backflow: veins or arteries?
Heart · Lungs · Digestive Tract
2. Which component of human blood contains haemoglobin and transports oxygen from the lungs to body tissues: red blood cells or platelets?
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 tiny cell fragments in blood help form clots at a wound to stop bleeding: platelets or red blood cells?
Heart · Lungs · Digestive Tract
5. 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
6. 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
7. 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
8. 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
9. 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
10. 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
11. Which digestive enzyme breaks down large starch molecules into simple sugars: amylase or lipase?
Heart · Lungs · Digestive Tract
12. 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

12 questions · Seed 47 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

Human body systems & organs

Answers and reasoning. Review before teaching.

1. 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.
2. Which component of human blood contains haemoglobin and transports oxygen from the lungs to body tissues: red blood cells or platelets?
Red blood cells
Red blood cells (erythrocytes) are packed with haemoglobin and lack a nucleus to maximise oxygen transport.
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 tiny cell fragments in blood help form clots at a wound to stop bleeding: platelets or red blood cells?
Platelets
Platelets trigger blood clotting to seal damaged vessels.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
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. 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.

12 questions · Seed 47 · Age guidance, not curriculum certification