Topic 9 — Human Biology and Ecology Investigations

1. Human Biology Experiments in ATP

Common investigations:

• pulse rate

• breathing rate

• exercise effect

• reaction time

• lung capacity

• temperature effect

• food and digestion experiments

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2. Pulse Rate Experiments

Pulse Rate

Number of heart beats per minute.

Usually measured:

• at wrist

• at neck

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3. Measuring Pulse Rate

Method

• count beats for 15 s

• multiply by 4

OR

count for full minute.

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4. Exercise Investigations

Usually compare:

• resting pulse rate

• pulse after exercise

• recovery time

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5. Expected Results

Exercise →
pulse rate increases

Reason:
more oxygen and glucose needed by muscles.

Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change.

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6. Breathing Rate Experiments

Breathing Rate

Number of breaths per minute.

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7. Measuring Breathing Rate

Count:

• chest rises
  OR

• breaths taken

Usually over:
1 minute

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8. Effect of Exercise on Breathing

Exercise →
breathing rate increases

Reason:
more oxygen needed
more carbon dioxide removed

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9. Reaction Time Experiments

Common ATP Method

Dropping ruler between fingers.

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10. Expected Trend

Shorter distance fallen →
faster reaction time

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11. Controlled Variables in Human Biology Experiments

Examples:

• same person

• same exercise duration

• same timing method

• same environmental conditions

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12. Sources of Error

Common Errors

• inaccurate timing

• counting mistakes

• different exercise intensity

• delayed reactions

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13. Improvements

• repeat experiment

• calculate averages

• use electronic sensors

• use larger sample size

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14. Ecology

Definition

Study of relationships between organisms and environment.

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15. Habitat

Place where organism lives.

Examples:

• pond

• forest

• desert

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16. Population

All members of one species in area.

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17. Community

All populations living together.

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18. Ecosystem

Community plus environment.

Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change.

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19. Sampling Techniques

Quadrat Sampling

Used for:
plants and slow-moving organisms.

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20. Quadrat

Square frame used for counting organisms.

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21. Random Sampling

Quadrat placed randomly.

Reason:
avoid bias

Very common ATP explanation.

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22. Transects

Line across habitat.

Used to study:
distribution of organisms.

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23. Types of Transects

Line Transect

Record organisms touching line.

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Belt Transect

Use quadrats along line.

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24. Population Estimation

Formula

mean number × total area

divided by

area sampled

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25. Common Ecology Variables

Abiotic Factors

• temperature

• light intensity

• pH

• moisture

• wind speed

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Biotic Factors

Living organisms.

Examples:

• predators

• disease

• competition

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26. Food Chains

Example

grass → rabbit → fox

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27. Producers

Make own food by photosynthesis.

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28. Consumers

Eat other organisms.

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29. ATP Ecology Graphs

Often involve:

• population size

• distribution

• environmental factors

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30. Interpreting Ecology Data

Common Trends

More light →
more plant growth

More moisture →
more organisms needing water

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31. ATP Ecology Questions

Frequently ask:

• identify pattern

• suggest reason

• explain distribution

• compare habitats

• calculate averages

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32. Pollution Experiments

May involve:

• effect on growth

• water quality

• oxygen levels

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33. Common ATP Conclusions

Strong Conclusion

“More plants were found in moist soil because water is required for growth.”

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Weak Conclusion

“Plants like water.”

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34. Reliability in Ecology

Improve by:

• larger sample size

• repeated sampling

• more quadrats

• random sampling

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35. Common Examiner Complaints

• confusing habitat/community/ecosystem

• forgetting random sampling

• vague ecology conclusions

• poor graph descriptions

• weak explanation of exercise effects

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36. ATP Frequently Tested Skills

Candidates may need to:

• count organisms

• calculate averages

• identify trends

• compare habitats

• explain ecological patterns

• suggest improvements

• interpret graphs/tables

• explain exercise data

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37. Human Biology ATP Graph Trends

Exercise

exercise increases:

• pulse rate

• breathing rate

Recovery:
rates gradually return to normal

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38. Ecology ATP Graph Trends

Population Curves

May show:

• increase

• decrease

• seasonal variation

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39. Quick Ecology Summary

Term	Meaning
Habitat	where organism lives
Population	one species in area
Community	all populations
Ecosystem	community + environment

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40. Quick Sampling Summary

Method	Use
Quadrat	plants/slow organisms
Transect	distribution studies

Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 11 World Records and 7 Distinctions, Educate A Change.