Mole rats, $Spalax\,ehrenbergi$, are mammals that live together in social groups in underground burrow systems, cannot see, and exchange information with one another by means of sound and scent. Males produce a purring call when they are trying to attract females for mating. In Israel, mole rats from different regions all appear identical. Even so, they actually belong to four distinct populations with different chromosome numbers, living in different climatic regions. These are shown in Table 5.1. This table also gives information about the purring calls used by the males in each population. The males’ calls were studied by counting the number of sound pulses per second, and also by measuring the frequencies of the sounds they produced.
(a)[2]
Explain why the chromosome number in each of the four mole-rat populations is an even number.
(b)[2]
With reference to Table 5.2, describe how far female mole rats show preference for the purring calls of males from their own population.
(c)[4]
Using the data in both Table 5.1 and Table 5.2, discuss whether these four mole-rat populations ought to be classified as different species.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Diploid state: two chromosome sets” …