C3.1 Integration of body systems questions for IB Biology

40 questions on Integration of body systems, written by Augment in the style of IB exam papers. Six of them are below in full, to answer on paper.

  • IB Biology
  • Part of C Interaction and interdependence
  • SL and HL

Questions by paper and level

SL and HL questions are for students at either level. HL only questions cover what only HL students study.

PaperSL and HLHL onlyAll
Paper 1A13720
Paper 1B325
Paper 211415
Every paper271340

Counted on

Questions to try

Written by Augment in the style of IB exams, not past papers. Answer them on paper, then check each one against its markscheme with a free account.

Question 1 · BIO-00829Paper 1A · 1 mark

A peregrine falcon (Falco peregrinus) can dive at more than 300 km h-1 and seize a flying bird in mid-air. Why is this hunting ability described as an emergent property?

  1. A

    It is controlled by a single gene expressed in its flight muscle cells

  2. B

    It arises from interactions between body systems and is not shown by any of the parts alone

  3. C

    It is the sum of the separate properties of each cell in the body

  4. D

    It is learned by each falcon from its parents during its first months of life

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Question 2 · BIO-00849Paper 1B · 8 marks

Students investigated the effect of exercise on heart rate and ventilation rate. Eight students sat at rest for 5 minutes and then stepped on and off a 30 cm step in time with a metronome for 3 minutes. Heart rate was measured with a pulse monitor and ventilation rate was found by counting breaths for 30 s. Measurements were taken at rest, at the end of the exercise and at intervals during recovery. The table shows the mean results.

Time / min

Stage

Mean heart rate / beats min-1

SD

Mean ventilation rate / breaths min-1

SD

0

rest

72

6

14

2

3

end of exercise

138

11

31

4

4

recovery

112

9

24

3

5

recovery

96

8

19

3

7

recovery

81

7

16

2

9

recovery

74

6

14

2

  1. (a)

    State one variable, other than the height of the step, that was controlled in this investigation.

    1 mark

  2. (b)

    Calculate the percentage increase in mean ventilation rate between rest and the end of the exercise.

    1 mark

  3. (c)

    Compare and contrast the changes in heart rate and ventilation rate during recovery.

    2 marks

  4. (d)

    Explain how the increase in ventilation rate during exercise is brought about.

    3 marks

  5. (e)

    Suggest one limitation of measuring ventilation rate by counting breaths.

    1 mark

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Question 3 · BIO-00826Paper 2 · 15 marks

Cells in multicellular organisms must communicate with each other.

  1. (a)

    Outline how a neuron generates and maintains its resting potential.

    4 marks

  2. (b)

    Explain how a signal is transmitted across a synapse between two neurons that use acetylcholine as a neurotransmitter.

    7 marks

  3. (c)

    Distinguish between nervous and hormonal signalling in animals.

    4 marks

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Question 4 · BIO-00830Paper 1A · 1 mark

Which row distinguishes correctly between signalling by the nervous system and by the endocrine system?

Row

Nervous system

Endocrine system

A

Signals reach all cells of the body

Signals reach only the target cells

B

Chemical signals carried in the blood

Electrical impulses carried by neurons

C

Effects are usually long-lasting

Effects are usually short-lived

D

Signals carried along neurons to specific cells

Signals carried in the blood to all parts of the body

  1. A

    All cells; only target cells

  2. B

    Chemical signals in blood; electrical impulses along neurons

  3. C

    Long-lasting; short-lived

  4. D

    Along neurons to specific cells; in blood to all parts of the body

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Question 5 · BIO-00850Paper 1B · 10 marks

Twenty students each measured their reaction time ten times in a row using a ruler-drop test. A partner held a 50 cm ruler vertically between the student's open thumb and finger and dropped it without warning. The student caught the ruler as soon as they saw it move, and the distance it fell was converted to a reaction time. The graph shows the mean reaction time for each trial. Error bars show ± one standard deviation.

Line graph with error bars: mean reaction time falls from 0.245 s at trial 1 to 0.201 s at trial 6, then levels off at about 0.195 s by trial 10. Error bars are about ±0.025 to ±0.03 s.
  1. (a)

    State the dependent variable in this investigation.

    1 mark

  2. (b)

    Calculate the percentage decrease in mean reaction time between trial 1 and trial 10.

    1 mark

  3. (c)

    Describe the trend in the results.

    2 marks

  4. (d)

    Suggest a reason for the decrease in reaction time over the trials.

    1 mark

  5. (e)

    Using the error bars, discuss whether reaction time continued to improve between trial 6 and trial 10.

    2 marks

  6. (f)

    Outline the pathway of nerve impulses from detection of the moving ruler to the contraction of the muscles that close the fingers.

    3 marks

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Question 6 · BIO-00828Paper 2 · HL only · 15 marks

The nervous system processes information through the interaction of many neurons.

  1. (a)

    Outline why consciousness is regarded as an emergent property of the brain.

    4 marks

  2. (b)

    Explain how excitatory and inhibitory neurotransmitters together determine whether a postsynaptic neuron transmits an impulse.

    7 marks

  3. (c)

    Describe the pain reflex arc that withdraws the hand from a sharp object.

    4 marks

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The notes on C3.1 Integration of body systems

More questions in Interaction and interdependence

  1. C1.1Enzymes and metabolism
  2. C1.2Cell respiration
  3. C1.3Photosynthesis
  4. C2.1Chemical signallingHL only
  5. C2.2Neural signalling
  6. C3.1Integration of body systemsThis page
  7. C3.2Defence against disease
  8. C4.1Populations and communities
  9. C4.2Transfers of energy and matter

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