📚 Lesson 1: Identify and Trace the Systems

WALT: We are learning to identify the main parts of the respiratory and circulatory systems and trace the movement of gases through the body.

Success criteria: I can name key organs and structures. I can describe the path of oxygen and carbon dioxide. I can use arrows and scientific vocabulary in a model.

Dyslexia-friendly option: Read one short line at a time. Use a ruler or coloured strip to track text. Take extra spacing between questions and ask for key words to be read aloud if needed.

_____ Oxygen diffuses from an alveolus into a capillary.

_____ Carbon dioxide diffuses from a muscle cell into a capillary.

_____ Air enters through the nose or mouth.

_____ Blood carries oxygen to the heart.

_____ Blood carries oxygen to the muscle.

_____ Carbon dioxide is carried to the lungs.

_____ Oxygen diffuses from the capillary into the muscle cell.

_____ Carbon dioxide is exhaled.

✏️ Lesson 2: Explain How the Systems Work Together

WALT: We are learning to explain how gas exchange and transport work together to supply cells with oxygen.

Success criteria: I can use the words alveoli, capillaries, haemoglobin and diffusion correctly. I can explain changes during exercise using evidence. I can model links between the two systems.

Word bank: alveoli   capillaries   diffusion   haemoglobin   oxygen   carbon dioxide

a. Gas exchange happens in tiny air sacs called __________.

b. __________ is the movement of particles from a higher concentration to a lower concentration.

c. __________ carries oxygen inside red blood cells.

d. Oxygen moves from the alveoli into nearby __________.

e. Cells use oxygen and produce __________ as a waste gas.

At rest: breathing rate = 14 breaths per minute; heart rate = 72 beats per minute.

After running: breathing rate = 32 breaths per minute; heart rate = 148 beats per minute.

What do these changes show about the body's needs during exercise?

✅ Answer Key and Support

1. 1–C, 2–E, 3–A, 4–B, 5–D.

2. 1–C, 2–E, 3–A, 4–D, 5–B.

3. In the order shown: 3, 6, 1, 4, 5, 7, 8, 2. The complete sequence is: air enters; oxygen diffuses into a capillary; blood carries oxygen to the heart; blood carries oxygen to the muscle; oxygen diffuses into the muscle cell; carbon dioxide enters a capillary; carbon dioxide is carried to the lungs; carbon dioxide is exhaled.

4. a. alveoli; b. diffusion; c. haemoglobin; d. capillaries; e. carbon dioxide.

5. Alveoli provide a large surface area, have very thin walls and are surrounded by many capillaries. This allows oxygen and carbon dioxide to diffuse quickly.

6. Capillaries bring blood close to muscle cells. Oxygen carried by haemoglobin diffuses from the blood into the cells.

7. Exercising muscles need more oxygen and produce more carbon dioxide. Breathing increases gas exchange, while the heart pumps blood faster to transport oxygen and remove carbon dioxide.

8. Both rates increase greatly after running. This shows that the muscles need more oxygen and faster removal of carbon dioxide during exercise.

9. Accept diagrams showing oxygen moving from air to alveoli, into capillaries, binding to haemoglobin, travelling through the heart to a muscle cell, and carbon dioxide returning to the lungs and leaving the body. The labels gas exchange, transport and cellular respiration should be included.

10. The respiratory system supplies oxygen and removes carbon dioxide. The circulatory system transports oxygen and glucose to muscle cells and carries carbon dioxide away. The muscle cell uses these materials in cellular respiration to release energy.

Differentiation strategies: Provide a labelled word bank, partially completed sequences and sentence starters such as “Oxygen diffuses from ___ to ___.” Pair learners for oral rehearsal before writing. Allow labelled drawings, speech-to-text or verbal answers. Pre-teach key vocabulary with picture cards and check understanding after each short instruction.

Extension activities: Compare gas exchange in the lungs and muscles. Explain how smoking or asthma could affect oxygen delivery. Design an investigation measuring breathing and heart rate before, during and after exercise, including a prediction and safe method.

Curriculum link: NZ Te Mātaiaho Science, Phase 3 Biological Science: gas exchange and modelling or explaining how the respiratory and circulatory systems work together. References: NZ-TMA-SCIENCE-Y0-10-biological-science-122-DOC205 and NZ-TMA-SCIENCE-Y0-10-biological-science-126-DOC205.