问题
单项选择题
用适宜浓度的生长素处理未受粉的番茄雌蕊柱头,可以得到无子番茄,这种果实细胞中的染色体数目为()
A.与卵细胞染色体数目一样
B.与体细胞中染色体数目一样
C.比受精卵染色体多一倍
D.与受精极核染色体数目一样
答案
参考答案:B
用适宜浓度的生长素处理未受粉的番茄雌蕊柱头,可以得到无子番茄,这种果实细胞中的染色体数目为()
A.与卵细胞染色体数目一样
B.与体细胞中染色体数目一样
C.比受精卵染色体多一倍
D.与受精极核染色体数目一样
参考答案:B
补全对话。(根据对话情景,选择适当的选项填入对话的空白处。) | |
A: 1__________ B: It is not big but beautiful. A: How many students are there in your class? B. 2_________ What about yours? A: Fifty students. 3_________ B: No, we have ten subjects. A: Then how many hours do you spend on homework every day? B: 4_______ A: That's a little longer. We only need two hours. 5_________ And we have to write reports about the books we read. | |
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