ï aqa-bio6x-qp-jun15 layout 1beechencliffschoolbiology.weebly.com/uploads/1/1/5/...mixture 1 d gas...
TRANSCRIPT
For Examiner’s UseTotal EMPA mark
Examiner’s Initials
Section Mark
Task 1
Task 2
Section A
Section B
TOTALEMPA MARK
General Certificate of EducationAdvanced Level ExaminationJune 2015
Biology BIO6XUnit 6X A2 Externally Marked Practical Assignment
Written Test
For submission by 15 May 2015
CentreNumber
CandidateNumber
Surname
Notice to Candidate. The work you submit for assessment must be your own. If you copy from someoneelse or allow another candidate to copy from you, or if you cheat in any other way, you may be disqualified.
Candidate Declaration. I have read and understood the Notice to Candidate and can confirm thatI have produced the attached work without assistance other than that which is acceptable under the schemeof assessment.
CandidateSignature
OtherNames
Date
For this paper you must have:
the Task Sheet 2, including your results and statistical calculations
a ruler with millimetre measurements
a calculator.
Time allowed
1 hour 15 minutes
Instructions
Use black ink or black ball-point pen.
Fill in the boxes at the top of this page.
Answer all questions.
You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages.
Do all rough work in this book. Cross through any work you do notwant to be marked.
Information
The marks for questions are shown in brackets.
The maximum mark for this paper is 35.
You are expected to use a calculator where
appropriate. You will be marked on your ability to:
– use good English– organise information clearly– use scientific terminology accurately.
Details of additional assistance (if any). Did the candidate receive any help or information in the production of this work? If you answer yes give the details below or on a separate page.
Yes No
As part of AQA’s commitment to assist students, AQA may make your coursework available on a strictly anonymous basis to teachers,examining staff and students in paper form or electronically, through the Internet or other means, for the purpose of indicating a typical markor for other educational purposes. In the unlikely event that your coursework is made available for the purposes stated above, you mayobject to this at any time and we will remove the work on reasonable notice. If you have any concerns please contact AQA.
To see how AQA complies with the Data Protection Act 1988 please see our Privacy Statement at aqa.org.uk.
WMP/Jun15/BIO6X/E5 BIO6X
Teacher Declaration:I confirm that the candidate has met the requirements of the practical skills verification (PSV) in accordance with theinstructions and criteria in section 3.8 of the specification.
Signature of teacher .................................................................................................................... Date .......................................
Practical Skills Verification Yes
2
WMP/Jun15/BIO6X
Do not writeoutside the
box
Section A
These questions relate to your investigation of how carbon dioxide affects the body.
Use your copy of Task Sheet 2, your results and your statistical analysis to answer the questions.
Answer all questions in the spaces provided.
6 You measured your own breathing rate (step 1). This may have affected your breathing rate.Suggest why.
[1 mark]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
7 You were told not to breathe in or out deeper than you would normally at rest (step 1).Explain why.
[1 mark]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
8 You started the investigation by using the minimum time of 10 seconds for holding yourbreath (step 3).Suggest why you were told to start with the minimum time.
[2 marks]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
3
9 You held your breath. You then started to breathe again and counted the number ofbreaths in the next 30 seconds (step 4). You used the result to calculate your breathingrate per minute.
Give two reasons why using the result for 30 seconds might not be a good method fordetermining breathing rate.
[2 marks]
1 ..........................................................................................................................................
............................................................................................................................................
2 ..........................................................................................................................................
............................................................................................................................................
Turn over for the next question
Do not writeoutside the
box
WMP/Jun15/BIO6X
Turn over �
4
10 Breathing rate (or ventilation rate) can be used to calculate pulmonary ventilation.Pulmonary ventilation is the volume of air breathed in per minute. A physiologist used amachine to record a person’s breathing at rest.
Figure 1 shows a chart recording his results.
Figure 1
Use Figure 1 to calculate pulmonary ventilation at rest for this person. Explain how youarrived at your answer.
[3 marks]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
Pulmonary ventilation = .................................................................
Do not writeoutside the
box
WMP/Jun15/BIO6X
00 20 40 60 80 100 120 140
1.0
2.0
0.5
1.5
2.5
Volume/ dm3
Time / seconds
5
11 In Task 1, you found the pH of universal indicator solution after blowing into it.Another student who did this found the pH to be 5.0.
Mechanisms that control heart rate also control breathing rate.
Use this information and your own knowledge to explain why a person’s breathing rateusually increases after they have held their breath.
[4 marks]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
[Extra space] .....................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
Turn over for the next question
Do not writeoutside the
box
WMP/Jun15/BIO6X
Turn over �
6
12 A principle of homeostasis is the maintenance of a constant internal environment.An increase in the concentration of carbon dioxide would change the internalenvironment and blood pH.Explain the importance of maintaining a constant blood pH.
[3 marks]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
[Extra space]......................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
Do not writeoutside the
box
WMP/Jun15/BIO6X
7
WMP/Jun15/BIO6X
Turn over �
13 Too much carbon dioxide in the air can be poisonous. The level of poisoning dependson the concentration of carbon dioxide in the air breathed in.
Table 6 shows some of the effects of different levels of poisoning.
Table 6
13 (a) You were not allowed to hold your breath for longer than 40 seconds during yourinvestigation.Suggest why.
[1 mark]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
13 (b) One effect of carbon dioxide poisoning is given as ‘confusion’.Is this a useful effect to look for to detect whether someone is suffering from carbondioxide poisoning? Give two reasons for your answer.
[2 marks]
1 ..........................................................................................................................................
............................................................................................................................................
2 ..........................................................................................................................................
............................................................................................................................................
Turn over for the Resource Sheet
Do not writeoutside the
box
Percentage carbon dioxide
in airEffects of carbon dioxide poisoning
1 Drowsiness
3Increased heart rateIncreased blood pressure
5DizzinessShortness of breathConfusion
8Muscle tremorSweatingUnconsciousness
19
8
WMP/Jun15/BIO6X
Resource Sheet
Resource A
A scientist used grasshoppers to investigate the effect of composition of air on breathing rate ininsects. He changed the composition of air they breathed in by varying the concentrations ofoxygen and carbon dioxide.
The scientist collected 20 mature grasshoppers from a meadow. He placed the grasshoppers in asmall chamber where he could adjust and control the composition of air surrounding them. Thesmall chamber restricted the movement of the grasshoppers.
His results for three of the grasshoppers are shown in Table 7 in the form in which he presentedthem.
Table 7
Percentage of oxygen and carbon dioxide in
different types of air breathed in by grasshoppers
A
Air from
atmosphere
B
Pure
oxygen
C
Gas
mixture 1
D
Gas
mixture 2
Gas
Oxygen 20.9 100.0 91.0 84.0
Carbon
dioxide0.1 0.0 9.0 16.0
Breathing
rate of
grasshopper
in different
types of air /
breaths per
minute
Grasshopper
153 11 99 107
Grasshopper
248 25 88 99
Grasshopper
361 13 96 93
9
WMP/Jun15/BIO6X
Turn over �
Resource B
A biologist investigated the effect of water temperature on the rate of ventilation of gills in a speciesof fish. She kept four fish in a thermostatically controlled aquarium and measured the meanventilation rate by counting movements of their gill covers.
Her results are shown in Figure 2.
Figure 2
In this investigation, the biologist also monitored the concentration of oxygen in the water in theaquarium. The concentration of oxygen in water changes with temperature of the water. Figure 3
shows how it changes.
Figure 3
0 10 20 305 15 25
Meanventilationrate offish
Water temperature / ºC
00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
10 20 30 35 405 15 25
Solubility ofoxygen / goxygen perkg water
Water temperature / ºC
10
Use Resource A to answer Questions 14 to 16.
14 The percentages of oxygen and carbon dioxide in Column A do not add up to 100% butin columns C and D they do.Suggest two reasons for this difference.
[2 marks]
1 ..........................................................................................................................................
............................................................................................................................................
2 ..........................................................................................................................................
............................................................................................................................................
15 Use all the data to describe the effect of concentration of carbon dioxide on thebreathing rate of grasshoppers.
[3 marks]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
[Extra space] .....................................................................................................................
............................................................................................................................................
............................................................................................................................................
Do not writeoutside the
box
WMP/Jun15/BIO6X
Section B
Use the information in the Resource Sheet and your own knowledge to answer the questions.
Answer all questions in the spaces provided.
11
16 One of the different types of air was similar to the air in the meadow where thegrasshoppers were collected. It provides data that might be used to calculate a meanbreathing rate for grasshoppers in the meadow.
16 (a) Use the data to estimate the mean breathing rate of the three grasshoppers in themeadow. Show your working.
[2 marks]
Mean breathing rate =................................................................. breaths per minute
16 (b) The estimate does not provide a reliable value for the mean breathing rate of all insectspecies in the meadow.Other than being an estimate, suggest and explain three reasons why this value wouldnot be reliable.
[3 marks]
1 ..........................................................................................................................................
............................................................................................................................................
............................................................................................................................................
2 ..........................................................................................................................................
............................................................................................................................................
............................................................................................................................................
3 ..........................................................................................................................................
............................................................................................................................................
............................................................................................................................................
Use Resource B to answer Questions 17 to 19.
17 Suggest a difficulty of counting movements of gill covers as a method of measuring rateof ventilation in fish.
[1 mark]
............................................................................................................................................
............................................................................................................................................
Do not writeoutside the
box
WMP/Jun15/BIO6X
Turn over �
12
18 The biologist concluded that there was a correlation between rate of ventilation of thegills and temperature of the water. A scatter diagram can be used to look for acorrelation but, in this investigation, it was not the appropriate graph for her data.Explain why.
[1 mark]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
19 (a) Describe the relationship between temperature of water, oxygen in water and rate ofventilation.
[1 mark]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
19 (b) Use Figure 2 and Figure 3 to explain the advantage to the fish of the change in its rateof ventilation.
[3 marks]
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
............................................................................................................................................
[Extra space] .....................................................................................................................
............................................................................................................................................
............................................................................................................................................
END OF QUESTIONS
Do not writeoutside the
box
WMP/Jun15/BIO6X
16
Copyright © 2015 AQA and its licensors. All rights reserved.