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IGCSE · Cambridge (CIE) · 0610

Investigate activity effects and breathing recovery

Plan a controlled comparison of both rate and depth with repeats and recorded recovery times.

Gas exchange in humans pathway · 11.1

Core and Extended; Biology 0610, 2026–2028. Use the stated specimen features and evidence. Diagrams are schematic. Written practice is self-checked

Before you begin

  • Recall separate rate and depth measures.

Work on paper. Try each question before revealing help, and explain why your method works.

Quick readiness check

Which two outcomes are required?

What you will learn

  • Measure both required outcomes
  • Control conditions and qualify conclusions

Investigate activity effects and breathing recovery

Invented paired outcomes: rest 12/min,0.50 L; immediate 24/min,0.75 L; later 16/min,0.60 L. Both rise then approach, but do not yet reach, baseline.Rest12/min; 0.50 LImmediate24/min; 0.75 LLater recovery16/min; 0.60 L
Invented paired outcomes: rest 12/min,0.50 L; immediate 24/min,0.75 L; later 16/min,0.60 L. Both rise then approach, but do not yet reach, baseline. Original teaching model.
Invented recovery observations — not a clinical measurement
ConditionRate / breaths per minDepth / L per breath
Rest120.5
Immediate240.75
Later recovery160.6

Measure both required outcomes

A useful investigation compares resting breathing with breathing after a stated, teacher-approved activity. Measure complete breaths per fixed interval for rate and use a suitable supervised observation or volume recording for depth. Keep the activity duration and intensity definition consistent, and state exactly when each post-activity measurement begins.

Supplied results show rest at 12 breaths/min with 0.50 L per breath, immediately after activity at 24/min and 0.75 L, and later recovery at 16/min and 0.60 L. Both rate and depth rise after activity and then move towards resting values. The last values are still above the stated baseline, so full recovery has not yet been demonstrated.

Control conditions and qualify conclusions

Compare repeated observations using the same timing, posture, recording method and stated activity. Different people, different activities or unequal delays can introduce additional variables. Record repeats and describe variation rather than calling one observation an exact rule for all students. A recovery curve needs its elapsed times and units labelled.

Use teacher-provided data when supervised measurement is unavailable. Any class activity must be appropriate to the participant, approved by the teacher and stopped if uncomfortable; written interpretation is not an instruction to perform strenuous exercise. The results describe breathing responses, not a health diagnosis, fitness ranking or proof of supervised practical competence.

Pause and explain

Which conclusion matches the supplied recovery data?

Put the idea to work

Worked example

Does a recovery result of 16/min and 0.60 L match a baseline of 12/min and 0.50 L?

Show the worked solution
  1. Compare each outcome.
  2. Both recovery values remain above baseline.

Answer No; both have moved towards baseline but have not returned to it in the supplied data.

Try a topic test

Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.

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From guided practice to a new situation

Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.

1 · Guided

State how both rate and depth change from rest to immediately after the supplied activity.

Give me a hint

Compare both columns.

Compare my reasoning
  1. Rate rises from 12 to 24/min.
  2. Depth rises from 0.50 to 0.75 L per breath.

Both increase: rate doubles and depth increases by 0.25 L per breath.

Look for these in your work

  • Describe both
  • Use the data
2 · Independent

Name three controls or recording choices that support a fair recovery comparison.

Give me a hint

Consider activity, timing and measurement.

Compare my reasoning
  1. Match stated activity and its duration.
  2. Use the same recording method and record exact post-activity delays.

Examples: matched activity/duration, same measurement method, same posture, and recorded equal post-activity intervals.

Look for these in your work

  • Give three relevant choices
  • Link them to comparability
3 · Transfer

One group measures immediately after activity and another waits three minutes. Can a lower second rate establish that its activity was easier?

Give me a hint

Recovery time is a confounder.

Compare my reasoning
  1. The waiting period differs.
  2. The lower rate could reflect recovery rather than activity difficulty.

No; unequal measurement delays confound that conclusion.

Look for these in your work

  • Identify the timing confounder
  • Avoid unsupported ranking

Common mistakes

  • Measuring rate while claiming depth was measured too.
  • Comparing unequal post-activity delays.
Recall without your notes

What can you explain now?

Which conclusion matches the supplied recovery data?

Compare with the explanation

Both outcomes rise then move towards baseline

The final values remain above rest.

After trying it yourself, choose your next review. This is your self-assessment.

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Make it stick

Plan both measurements and explain why recovery timing must be recorded.

If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.

Keep learning Biology

Course scope and assessment

780 sequenced lessons provide 2340 guided, independent and application problems in characteristics, classification, cells, organisation, specimen size, membrane transport, biological molecules, enzymes, plant and human nutrition, plant transport, circulatory systems, the heart, blood vessels, blood, disease transmission, body defences, immunity, gas exchange in humans, respiration energy uses and investigations, aerobic respiration, anaerobic respiration and recovery, excretion in humans, coordination and response, sense organs, hormones, homeostasis, tropic responses, drugs, asexual reproduction, sexual reproduction, sexual reproduction in plants, sexual reproduction in humans, sex hormones in humans, sexually transmitted infections, chromosomes, genes and proteins, mitosis, meiosis, monohybrid inheritance, variation, adaptive features, selection, energy flow, food chains and webs, nutrient cycles, population, community, ecosystem, population-growth phases, food supply, habitat destruction, pollution, conservation, biotechnology and genetic modification. 61 of 61 syllabus sections have linked teaching and staged practice. The earlier inheritance overview remains introductory, and the monohybrid pathway develops the relevant Core and Supplement requirements. This is not full programme completion or guaranteed exam readiness. Written practice is self-checked.

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Original teaching content and links to official sources. Check your exam year and qualification before using a resource.