(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:2)(cid:8)(cid:44)
(b) Fig. 7.3 shows the evolutionary relationships between three species of American spadefoot
toad.
Spea multiplicata
Spea hammondii
Spea bombifrons
Question
Biology
CAIE2024
(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:2)(cid:8)(cid:44)
(b) Fig. 7.3 shows the evolutionary relationships between three species of American spadefoot
toad.
Spea multiplicata
Spea hammondii
Spea bombifrons
A roundabout completes 5.0 revolutions in 20 s.
Which of the following is the angular velocity of the roundabout?
A 1.6 rad s−1
B 16 rad s−1
C 25 rad s−1
D 630 rad s−1
(Total for Question 8 = 1 mark)
*P74468A0424*
(a) Describe why variation is important in natural selection. [6]
(b) Explain the role of isolating mechanisms in the evolution of new species. [9]
[Total: 15]
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University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
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UCLES 2007 9700/4/SP07 final
*P69306A01728*
Turn over
PMT
(b) The motor rotates at 500 revolutions per minute.
Calculate the angular speed ω of the motor.
(2)
...................................................................................................................................................................................................................................................
...................................................................................................................................................................................................................................................
ω =
.......................................................
(c) The table shows how the turning effect exerted on a load varies with ω for a
particular distance between the copper disc and the plastic disc.
ω / rad s−1 Turning effect / N cm
The blade of a lawnmower rotates at a speed of 50 revolutions per second.
Which of the following is the angular speed of the blade in rads s−1?
A 7.96
B 15.9
C 157
D 314
(Total for Question 9 = 1 mark)