题干

下图是两种二倍体植物细胞(甲、乙)融合并培育新植株过程的示意图。有关分析正确的是(    )

A:过程①需用纤维素酶和果胶酶溶液处理,且溶液的渗透压略大于细胞液渗透压

B:过程②可用聚乙二醇诱导原生质体融合,主要依据细胞膜具有选择透过性原理

C:过程③表示细胞壁的再生,④⑤需要根据生长发育进程更换不同的液体培养基

D:最终得到的植株相对于甲、乙而言发生了染色体数目变异,因此不具有可育性

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A

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    In 1975, George Carlin appeared on a popular TV show, Saturday Night Live, with his famous words about blue food. “Why is there no blue food? I can't find blue food—I can't find the flavor of blue! I mean yellow is lemon; orange is orange and red is cherry. Where is the blue food?”

    Well, Carlin pretty much has it right—there is not no blue food, but there's certainly not a lot of it. Fresh-picked blueberries are blue, though they become purple when they are turned into jam. The blue in blueberries—like the purple in grapes and red in tomatoes—is found in nature. But it isn't a hot color for food. People don't seem to prefer blue food. Some diet programs even suggest that those determined to lose weight should make their food blue.

    Eating, in part, begins with our eyes. Chares Spence—an experimental psychologist from Oxford University—points out that color can change our taste experience. Commonly, we consider red-colored foods up to 20% sweeter than they actually are; and green foods as being more sour. Spence suggests: human expectations may be influenced by our long history of watching—green fruits can become sweet as they grow up and turn red.

    But what about blue? Except blueberries, much of the blue food we see these days is dyed blue artificially. Food producers argue that artificial color doesn't do much damage to health. A lot of research shows that some physical problems of kids are related to food dyes—while other studies show no effects at all. Blue birthday cake or even blue-dyed chicken can be served on the dinner table. So what?