APRIL EXAMINATIONS: LIFE SCIENCES
GRADE 11
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LIFE SCIENCES PAPER: PRACTICAL COMPONENET MEMO
GRADE 11
APRIL 2022
Examiner: M TREVELYAN
Time: 1 HOUR
Moderator: S NCUBE
Total: 45 Marks
INTERPRETING DATA ON BREATHING RATE AND HEART RATE
1. Identify the dependent variable.
a. HEART RATE AND BREATHING RATE
_(2)
2. Identify the independent variable
a. Exercise
(2)
3. Write up a hypothesis:
(3)
a. The more one exercises,
b. The faster the breathing rate a
c. and the heart rate increases
4. Identify two control variables.
(2)
a. Cycled for 15 min
b. On the same bicycle
c. At the same pace
5. How could Kelly and Rutvi ensure that the results of their investigation
are reliable?
a. They could repeat the experiment,
b. 3 x
c. They could get more people to /
d. bigger sample to do the experiment
(4)
6. Why was it important that the girls carried out the same amount of
exercise?
They ensued the validity of the experiment so that is is failr
(2)
7. At rest, Kelly's breathing rate and heart rate were different from Rutvi's.
What effect might this have on the results of the investigation?
They have different fitness levels_
The experiment is not reliable
The people should have similar fitness levels_
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(3)
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APRIL EXAMINATIONS: LIFE SCIENCES
GRADE 11
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8. Draw a line graph to show Kelly and Rutvi’s heart rate.
(8)
Rubric for assessment of the graph
Criterion
Mark Allocation
Correct type of graph
(T)
1
Caption for graph
(C)
1
1
Correct label for X
Correct label and unit for Y-axis (%) (L)
Equal width and interval of bars
Correct scale for Y-axis
(S)
1
Required LINES PLTTED drawn
(N)
1 Only REQUIRED bars drawn
Drawing of
(B)
1 All 6 REQUIRED bars drawn
correctly
NOTE:
If the wrong type of graph is drawn: marks will be lost for ‘correct type of graph’.
If a line graph is drawn marks will also be lost for drawing of bars.
If axes are transposed: marks will be lost for labelling and scaling of X-axis and Y-axis
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APRIL EXAMINATIONS: LIFE SCIENCES
GRADE 11
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9 ) Suggest why the girls measured their breathing rate and heart rate before
the exercise.
This is the starting point at rest, they are then able to work out the difference/
increase in heart and breathing rate
(2)
10) Could this variable be controlled? Explain.
No, the people taking place should be of similar/ close to the same heart
and breathing rate
(2)
11) Describe the shape of the curve in the graph of Rutvi's breathing rate.
_
Ruttvi’s breathing and heartrate max 100bpm is lower than Kellys, Rutvi
also recovers quicker
12) The girls heart rates also increased during exercise, but by different
amounts.
Which student showed the greatest increase in the heart rate?
(1)
Kelly
13) Explain why the girls' heart and breathing rates both increased during
exercise.(2)




As they exercise they need to produce more energy
The Heart beats faster
To pump more oxygen to the cells
For cellular respiration to take place
(4)
DRAW A CONCLUSION FROM THE RESULTS
14) What trends does the graph show in relation to heart rate and breathing
rate of Kelly and Rutvi.?
For both girls as heart rate increases so does breathing rate
Rutvhi breathing and heart rate is not as high as Rutvi rate
(4)
15) Use scientific knowledge to explain why these changes took place.
Include information about changes to the rate of respiration and diffusion.
To produce energy our bodies must undergo
Cellular respiration,
For respiration to take place we need oxygen
Our hearts pump oxygen around the body
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APRIL EXAMINATIONS: LIFE SCIENCES
GRADE 11
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In order to get more oxygen to the cells our breathing rate must also increase
This is controlled by the autonomic nervous system
(4)
16) Explain who is fitter – Kelly or Rutvi?
(2)
Rutvi is fitter than Kelly
because her heart rate does not pump as much as Kelly in order
to do the same amount of exercise
APRIL 2022
Examiner: M TREVELYAN
Moderator: S NCUBE
Copyright HFS @2022
Time: 1 HOUR
Total: 45 Marks
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