CIE iGCSE Co-Ordinated Science B17.2 Selection Exam Style Questions Paper 2
▶️ Answer/Explanation
Random mutations occasionally give some bacteria resistance to an antibiotic.
When the antibiotic is used, non-resistant bacteria die while resistant ones survive and reproduce — this is natural selection, not human-directed breeding.
✅ Answer: (C)
When the antibiotic is used, non-resistant bacteria die while resistant ones survive and reproduce — this is natural selection, not human-directed breeding.
✅ Answer: (C)
▶️ Answer/Explanation
Selective breeding is a human-controlled process in which breeders choose parents with desirable characteristics, so it is called artificial selection, not natural selection.
Natural selection instead happens without human choice, driven by survival and reproduction in the wild.
Changing “natural” to “artificial” is the only edit that makes the statement scientifically accurate.
✅ Answer: (D)
Natural selection instead happens without human choice, driven by survival and reproduction in the wild.
Changing “natural” to “artificial” is the only edit that makes the statement scientifically accurate.
✅ Answer: (D)
▶️ Answer/Explanation
The black form of the moth first appeared as the result of a mutation, a random genetic change producing a new allele.
No human breeding programme selected the moths, so the shift in proportions is due to natural selection, not artificial selection.
Black moths were better camouflaged and survived better on polluted, darker tree bark, and pale moths survived better once pollution decreased.
✅ Answer: (D)
No human breeding programme selected the moths, so the shift in proportions is due to natural selection, not artificial selection.
Black moths were better camouflaged and survived better on polluted, darker tree bark, and pale moths survived better once pollution decreased.
✅ Answer: (D)
▶️ Answer/Explanation
Producing new combinations of alleles for humans to select from requires sexual reproduction, since asexual reproduction gives genetically identical offspring.
Farmers deliberately choosing and breeding the best egg-laying chickens is an example of human (artificial) selection, not natural selection.
Together this means sexual reproduction combined with human selection is needed, matching option C.
✅ Answer: (C)
Farmers deliberately choosing and breeding the best egg-laying chickens is an example of human (artificial) selection, not natural selection.
Together this means sexual reproduction combined with human selection is needed, matching option C.
✅ Answer: (C)
Question
The boxes show the steps involved in artificial selection of an animal species.
Which sequence of steps is correct?
(A) 2 → 1 → 4 → 3
(B) 2 → 4 → 3 → 1
(C) 4 → 3 → 2 → 1
(D) 4 → 2 →1 → 3
▶️Answer/Explanation
Ans : D