本题目来源于试卷: Unity and Diversity A.8 Evolution and Speciation，类别为 IB生物学
[单选题]
Which of the following ah4a4pdxynfl vghu d.or,j5w3-1+.t u re 2dvtd eyu0w 1+often barriers to hybridisation between species?
I. A given animal hybrid species has an even, as opposed to an odd number of chromosomes.
II. Two species of flowering plants produce gametes at different times of the year.
III. Behavioural barriers exist due to variations in bird song between species.
A. I and III only
B. II only
C. I and II only
D. II and III only
参考答案: D
本题详细解析:
Choice D is correct. Cross-pollination is unlikely if two species of flowering plants produce gametes at different times of year (Statement II). Mating, and thus hybridisation, is unlikely or impossible if members of one bird species fail to recognise the mating calls of another bird species (Statement III). Statement I is not a barrier to hybridisation because, typically, animals with even numbers of chromosomes in their somatic cells can reproduce sexually, but those with odd numbers are usually sterile due to an inability of their cells to undergo meiosis.
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