Biology · Oct / Nov 2023 · Paper 61 · Question 1
0610
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The question as text
Emperor penguins are large birds found in Antarctica where temperatures can be very low. Fairy penguins are small birds that live in Australasia where temperatures are much warmer. The body temperature of both species of penguin is maintained at approximately 38°C. A student investigated the rate of heat loss from a penguin with a large body compared with a penguin with a small body. They used a 250 cm3 beaker to represent the emperor penguin and a large test-tube to represent the fairy penguin. The student used this method: Step 1 Label the beaker A and the test-tube B. Step 2 Draw a line on beaker A and test-tube B 5 cm up from the bottom. Step 3 Use hot water to fill beaker A up to the 5 cm mark. Step 4 Place a thermometer in the water in beaker A. When the reading on the thermometer has stopped rising, measure the temperature of the water. Record this as the starting temperature. Leave the thermometer in the water throughout the investigation. Step 5 Start the stop-clock. Step 6 After one minute, measure and record the temperature of the water in beaker A. Step 7 Measure and record the temperature of the water in beaker A every minute for a total of five minutes. Step 8 Add hot water to test-tube B up to the 5 cm mark. Step 9 Repeat steps 4 to 7 using test-tube B instead of beaker A. 4 Fig. 1.1 shows the notes the student made about the results for the first four minutes. starting temperature for beaker A was 80 °C and for test-tube B was 79 °C beaker A 1 minute = 69.5 °C 2 = 62 °C 3 = 55.5 °C 4 = 51 °C 5 = test-tube B 1 minute = 65.5 °C 2 = 52 °C 3 = 47 °C 4 = 41 °C 5 = Fig. 1.1 Fig. 1.2 shows the thermometers for beaker A and test-tube B at five minutes. beaker A 60 °C 50 40 30 test-tube B 60 °C 50 40 30 Fig. 1.2
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1(a)(i)[4]
1
table drawn with at least three, columns with a line separating the headings from the body of the table ;
2
suitable headings with units for temperature (in) o C and time (in) minutes / s ;
3
six times and temperatures recorded for both A and B and correct recording of temperatures for 5 minutes ; 4
values for all results recorded to one decimal place ;
1(a)(ii)[3]
rate of heat loss for A = 6.4 ;
rate of heat loss for B = 8.8 ;
correct unit stated i.e. °C per minute ;
1(a)(iii)[1]
any one from:
the larger the penguin, the lower the rate of heat loss ;
large penguins lose heat more slowly (than small penguins) ;
1(b)(i)[1]
the size of the container / AW ;
1(b)(ii)[1]
any one from:
starting temperature of the water ;
temperature of, environment / surroundings / room ;
material the containers are made from ;
total time ;
sampling time / measure every minute ;
height of water on each container ;
AVP ;
1(c)(i)[6]
independent variable:
1
at least two different temperatures ;
detail of method:
2
method of maintaining different temperatures ;
3
method of cutting agar cubes ;
4
enough acid to cover cubes / AW ;
5 & 6 & 7 variables kept constant – max three from: ;;;
same, size agar cubes / shape of agar (cubes)type of agarconcentration / pH, of acidvolume of acidtype of acid / named acidsame type of indicator / named indicatordependent variable:
8
time taken for cube to become (completely) colourless or
idea of after a set period of time how much of the cube has become colourless ;
9
ref. to at least two further replications / repeat investigation two more times ;
10 relevant safety precaution e.g. goggles / gloves / cut agar on a solid surface / cut away from hands / AW ;
1(c)(ii)[2]
(surface area) 6 ; (: volume) 1 ;
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