1.
Fossils provide important evidence for evolution.
(a)
Outline how radioisotopes can be used to date fossils.
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(2)
(b)
The half-life of the radioisotope 14C is approximately 5730 years.
Using the decay curve shown above, deduce the age of a fossil that contains 30% of the
original amount of 14C.
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(1)
IB Questionbank Biology
1
(c)
Describe two major trends that can be seen from fossil remains in the sequence
Ardipithecus ramidus, Australopithecus species and Homo species.
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(2)
(Total 5 marks)
2.
(a)
State two processes needed for the spontaneous origin of life on Earth.
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(2)
(b)
Outline the properties of RNA that may have allowed it to play a role in the origin of life.
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(2)
(Total 4 marks)
IB Questionbank Biology
2
3.
(a)
Describe transient polymorphism.
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(3)
(b)
Explain how punctuated equilibrium affects the pace of evolution.
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(4)
(Total 7 marks)
4.
(a)
Describe the processes needed for the spontaneous origin of life on Earth.
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(3)
IB Questionbank Biology
3
(b)
Discuss the endosymbiotic theory for the origin of eukaryotes.
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(3)
(Total 6 marks)
5.
(a)
Describe two major anatomical features of humans that define them as primates.
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(2)
(b)
Discuss the implications of the incompleteness of the fossil record on our understanding
of human evolution.
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(3)
(Total 5 marks)
IB Questionbank Biology
4
6.
(a)
Define the term gene pool.
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(1)
(b)
Compare allopatric speciation and sympatric speciation.
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(4)
(c)
Explain the correlation between the change in diet and increase in brain size during
hominid evolution.
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(2)
(Total 7 marks)
7.
(a)
Define sympatric speciation.
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(1)
IB Questionbank Biology
5
(b)
Describe two examples of barriers between gene pools.
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(4)
(Total 5 marks)
IB Questionbank Biology
6