Biology 9700 · AS & A Level · Natural and artificial selection
Natural and artificial selection — practice question
All dog breeds that are modern belong to one species and are considered to have come from 14 ancient breeds through artificial selection. The golden retriever is a modern breed that is frequently used as a guide dog for people who are blind or visually impaired. Fig. 1.1 shows a golden retriever.
(a)[4]
Explain how artificial selection could have been used to breed golden retrievers with the characteristics needed for a guide dog.
(b)
(b(i))[2]
Suggest the kind of isolating mechanism that prevents:
• interbreeding among the three species of jackal
• the dingo from mating with every other member of the genus Canis except the domestic dog.
(b(ii))[2]
Using the information in Fig. 1.2 and Table 1.1, state:
• one reason why the members of the genus Canis might be described as one species
• one reason why they ought to be described as separate species.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “(desired characteristics) selected by humans / artificial selection” …