Q1.
Lipase is an enzyme that digests fat.
(a)     (i)      Complete the equation to show the digestion of fat.
Use the correct answer from the box.
 
glucose	glycerol	glycogen	
fat   fatty acids + ___________________
(1)
(ii)     Name one organ that makes lipase.
______________________________________________________________
(1)
(b)     Some students investigated the effect of bile on the digestion of fat by lipase.
The students:
1        mixed milk and bile in a beaker
2        put the pH sensor of a pH meter into the beaker
3        added lipase solution
4        recorded the pH at 2-minute intervals
5        repeated steps 1 to 4, but used water instead of bile.
Suggest two variables that the students should have controlled in this investigation.
1. _________________________________________________________________
___________________________________________________________________
2. _________________________________________________________________
___________________________________________________________________
(2)
(c)     The graph shows the students’ results.
 
(i)      Why did the pH decrease in both investigations?
______________________________________________________________
______________________________________________________________
(1)
(ii)     Bile helps lipase to digest fat.
What evidence is there in the graph to support this conclusion?
______________________________________________________________
______________________________________________________________
(1)
(iii)    Suggest one reason why the contents of both beakers had the same pH at the end of the investigations.
______________________________________________________________
______________________________________________________________
(1)
(Total 7 marks)
Q2.
(a)     Diagram 1 shows part of the breathing system.
Diagram 1
 
(i)      Use words from the box to name the parts labelled A, B, C and D.
 
alveolus	diaphragm	lung	rib	trachea	
A ____________________________
B ____________________________
C ____________________________
D ____________________________
(4)
(ii)     Parts B and C move when we breathe in.
Part B moves ____________________________________________
Part C moves ____________________________________________
(2)
(b)     A student used the apparatus shown in Diagram 2 to measure the maximum volume of air that he could breathe in one breath.
When the student breathes in, the piston moves upwards.
The piston moves back down after the student has breathed out.
Diagram 2
 
The student breathes in through the apparatus three times.
The drawings show the position of the piston after each of the three breaths.
The volumes are measured in cm3.
 
(i)      Read the volume of each breath and write the volume in the table.
 
 	Breath 1	Breath 2	Breath 3	
 Volume in cm3	___________	___________	___________	
(3)
(ii)     Calculate the mean volume of air breathed in.
______________________________________________________________
______________________________________________________________
Mean volume of air breathed in = ___________________ cm3
(2)
(c)     A teacher asks the student to investigate if students who take part in sports activities can breathe in a larger volume of air than students who do not take part.
Describe briefly how the student could use the same apparatus to do the investigation.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
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(3)
(d)     Photograph 1 shows a different piece of apparatus used to measure the volume of air that a person can breathe in one breath.
Photograph 1
 
© Digital Vision/Photodisc
When the student breathes out through the apparatus the pointer on the scale moves. The pointer stays in the same position when the student has finished.
Explain one advantage, apart from size, of using this apparatus rather than the apparatus described in part (b).
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(e)     Photograph 2 shows one type of mechanical ventilator.
Photograph 2
 
© Emine Donmaz/iStock
(i)      Use information from Photograph 2 to suggest how this type of ventilator works.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(ii)     Use information from Photograph 2 to suggest two disadvantages of this type of ventilator.
1. ____________________________________________________________
______________________________________________________________
2. ____________________________________________________________
______________________________________________________________
(2)
(Total 20 marks)
Q3.
(a)     A person cut his finger. A small amount of blood flowed from the cut but soon stopped due to blood clotting.
The following sentences describe what happens when a person has a small cut and a blood clot is formed.
Draw a ring around the correct answer to complete each sentence.
(i)      The tiny blood vessels near the surface of the skin that are damaged
 
are	arteries.
capillaries.
veins.	
(1)
(ii)	Blood clotting is stimulated by	platelets.
red blood cells.
white blood cells.	
(1)
(iii)	During blood clotting	fibrinogen changes to fibrin.
haemoglobin changes to oxyhaemoglobin.
lipid changes to fatty acids.	
(1)
(b)     A blood transfusion is when a person is given blood from a donor.
A person has lost a lot of blood and needs a blood transfusion.
It is important to use blood of the correct blood group. If blood of the wrong blood group is used, the transfusion will not be safe.
The person giving the blood is called the donor.
The person receiving the blood is called the recipient.
Complete the table to show which transfusions are safe and which are unsafe.
Some of the table has been completed for you as an example.
Use the following symbols:
 = a safe transfusion
 = an unsafe transfusion
Donor blood group and antigens
 
(3)
(c)     (i)      Anti-B antibodies will bind only to the B antigen. They will not bind to the A antigen.
Explain why.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(2)
(ii)     Red blood cells have a diameter of about 8 micrometres.
Some capillaries have an internal diameter of about 10 micrometres.
Red blood cells, with antibodies bound to them, stick together.
B antigens are found on the surface of red blood cells in people who have blood group B.
Use this information to explain why transfusion of group B blood into a person of blood group A is unsafe.
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
(3)
(Total 11 marks)
Q4.
Explain how the human circulatory system is adapted to:
•        supply oxygen to the tissues
•        remove waste products from tissues.
_______________________________________________________________________
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_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
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(Total 6 marks)
Q5.
LDL is one form of cholesterol found in the blood.
People with a high concentration of LDL in their blood may be treated with drugs called statins.
A high concentration of LDL cholesterol in the blood may result in an increased risk of heart and circulatory diseases.
The graph shows the effects of the treatment of one person with four different statins, 
A, B, C and D, over a period of 8 years. The arrows show when each new treatment was started.
Each treatment was continued until the next treatment was started.
 
Year
Compare the effectiveness of the five treatments in reducing the risk of heart and 
circulatory diseases for this person.
_______________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________
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(Total 4 marks)
Q6.
During exercise, the heart beats faster and with greater force.
The ‘heart rate’ is the number of times the heart beats each minute.The volume of blood that travels out of the heart each time the heart beats is called the ‘stroke volume’.
In an investigation, Person 1 and Person 2 ran as fast as they could for 1 minute. Scientists measured the heart rates and stroke volumes of Person 1 and Person 2 at rest, during the exercise and after the exercise.
The graph below shows the scientists’ results.
 
(a)     The ‘cardiac output’ is the volume of blood sent from the heart to the muscles each minute.
              Cardiac output = Heart rate × Stroke volume
At the end of the exercise, Person 1’s cardiac output = 160 × 77 = 12 320 cm3 per minute.
Use information from Figure above to complete the following calculation of Person 2’s cardiac output at the end of the exercise.
At the end of the exercise:
Person 2’s heart rate        = _______________ beats per minute
Person 2’s stroke volume = _______________ cm3
Person 2’s cardiac output = _______________ cm3 per minute
(3)
(b)     Person 2 had a much lower cardiac output than Person 1.
(i)      Use information from Figure above to suggest the main reason for the lower cardiac output of Person 2.
______________________________________________________________
______________________________________________________________
(1)
(ii)     Person 1 was able to run much faster than Person 2.
Use information from Figure above and your own knowledge to explain why.
______________________________________________________________
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(5)
(Total 9 marks)

Mark schemes
Q1.
(a)     (i)      glycerol
1
(ii)     pancreas / small intestine
accept duodenum / ileum
ignore intestine unqualified
1
(b)     any two from:
•         type of milk
•         volume / amount of milk
•         vol. bile equals vol. water
•         volume of lipase
•         concentration of lipase
•         temperature
ignore time interval
ignore solution unqualified
do not allow pH
ignore starting pH
ignore volume / amount of bile / water
ignore concentration of bile
accept amount of lipase if neither volume nor concentration given
2
(c)     (i)      fatty acid (production)
1
(ii)     faster reaction / digestion (with bile)
or
pH decreases faster (with bile)
or
takes less time (with bile)
or
steeper fall / line (with bile)
allow use of data
ignore easier
1
(iii)    all fat / milk digested
or
same amount of fatty acids present
or
(lower pH) denatures the enzyme / lipase
allow all reactants used up
ignore reference to neutralisation
allow enzyme won’t work at low pH
do not allow enzyme killed
1
[7]
Q2.
(a)     (i)      A lung
1
B rib
1
C diaphragm
1
D alveolus / alveoli
1
(ii)     (B moves) up(wards) / out / up and out
1
(C moves) down(wards) / flattens
do not allow inwards
ignore outwards
if neither mark gained allow 1 mark for correct reference to muscle contraction
1
(b)     (i)      1640
1
1440
1
1720
allow max 1 for 3 correct values using of bottom of piston:
1380 + 1180 + 1480 to 1485
1
(ii)     1600
correct answer gains 2 marks
if answer incorrect allow 1 mark for evidence of
(1640 + 1440 + 1720) ÷ 3
allow ecf from (b)(i)
allow use of two numbers divided by two if one is considered anomalous:
  = 1680
for 2 marks
2
(c)     two groups of students − one group sports activity participants, other not
allow students as a group
1
fair test eg groups same height / same mass / same sex
1
measure air breathed in by each student / repeat previous experiment then calculate mean for group
1
(d)     pointer remains still after breathing / cylinder will move down after breathing (in)
1
error reading volume less likely
allow more accurate / reliable
1
(e)     (i)      operator squeezes bag
1
air forced / pushed into lungs
or
positive pressure ventilator
1
(ii)     any two from:
•        air pressure / volume not regulated
•        operator will tire / must be present at all times / variable intervals
•        too much / too little air
allow may ‘overbreathe’ the patient
2
[20]
Q3.
(a)     (i)      capillaries
1
(ii)     platelets
1
(iii)    fibrinogen changes to fibrin
1
(b)     
 
1 mark per correct row
or
1 mark per correct column
whichever is greater
3
(c)     (i)      antibody / antigen has specific shape
ignore active site
1
antibody fits antigen / has shape complementary to antigen
1
(ii)     group A has anti-B antibodies which bind to B-antigens
1
join / clump RBCs together so too big to pass through capillary / block capillary
1
any one consequence: lack of O2 / food / blood supply to body cells or cells can’t respire
ignore ‘cells die’ / ‘person dies’ - look for cause
1
[11]
Q4.
Level 3 (5–6 marks):
A detailed and coherent explanation is provided with most of the relevant content, which demonstrates a comprehensive understanding of the human circulatory system . The response makes logical links between content points.
Level 2 (3–4 marks):
The response is mostly relevant and with some logical explanation. Gives a broad understanding of the human circulatory system. The response makes some logical links between the content points.
Level 1 (1–2 marks):
Simple descriptions are made of the roles of some of the following: heart function, gas exchange, named blood vessels, named blood cells. The response demonstrates limited logical linking of points.
0 marks:
No relevant content.
Indicative content
•        dual / double circulatory system which means that it has higher blood pressure and a greater flow of blood to the tissues
•        heart made of specialised (cardiac) muscle cells which have long protein filaments that can slide past each other to shorten the cell to bring about contraction for pumping blood
•        heart pumps blood to lungs in pulmonary artery so that oxygen can diffuse into blood from air in alveoli
•        blood returns to heart via pulmonary vein where muscles pump blood to the body via aorta
•        oxygen carried by specialised cells / RBCs which contain haemoglobin to bind oxygen and have no nucleus so there is more space available to carry oxygen
•        arteries carry oxygenated blood to tissues where capillaries deliver oxygen to cells for respiration and energy release
•        thin walls allow for easy diffusion to cells
•        large surface area of capillaries to maximise exchange
•        waste products removed eg CO2 diffuse from cells into the blood plasma
•        blood goes back to the heart in veins which have valves to prevent backflow
•        cardiac output can vary according to demand / is affected by adrenaline
accept annotated diagrams
[6]
Q5.
A + B most effective (treatment)
ignore descriptions of LDL levels
1
D is (the most) effective (treatment)
D is the best single (treatment)
1
neither A nor B (alone) are effective
allow increase risk of heart disease instead of not effective
1
can’t tell if C is effective
OR
A + C is not effective
1
[4]
Q6.
(a)     5624
allow 2 marks for:
•        correct HR = 148 and correct SV = 38 plus wrong answer / no answer
or
•        only one value correct and ecf for answer
allow 1 mark for:
•        incorrect values and ecf for answer
or
•        only one value correct
3
(b)     (i)      Person 2 has low(er) stroke volume / SV / described
eg Person 2 pumps out smaller volume each beat
do not allow Person 2 has lower heart rate
1
(ii)     Person 1 sends more blood (to muscles / body / lungs)
1
(which) supplies (more) oxygen
1
(and) supplies (more) glucose
1
(faster rate of) respiration or transfers (more) energy for use
ignore aerobic / anaerobic
allow (more) energy release
allow aerobic respiration transfers / releases more energy (than anaerobic)
do not allow makes (more) energy
1
removes (more) CO2 / lactic acid / heat
allow less oxygen debt
or less lactic acid made
or (more) muscle contraction / less muscle fatigue
if no other mark awarded,
allow person 1 is fitter (than person 2) for max 1 mark
1
[9]