本题目来源于试卷: Continuity and Change D.8 Inheritance，类别为 IB生物学
[单选题]
Mendel studied eight characterisg:x4 ataco *9ftics of pea plants, includie5*pybr o4 +3; lojo-i)oymrted u3/ zng flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of thesmj ielo-+)/3rtb pu d*r43oyz e;o5oye statements was correct?
A. Pea plants show co-dominance for flower colour
B. Flower colour is an example of polygenic inheritance
C. Flower colour is controlled by genes at two loci
D. Pea plants have two alleles for flower colour
参考答案: D
本题详细解析:
Two different colours show that there are two alleles for this characteristic (Choice D). Polygenic inheritance results in continuous variation (Choice B). Two distinct colours are an example of discontinuous variation. If there was co-dominance, there would be three possible flower colour variations (Choice A). If there were genes at two loci that controlled flower colour, then the trait would be a polygenic trait and show continuous variation (Choice C).
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