通过实验研究洋葱根尖细胞有丝分裂过程，得出下图所示的结果，其中图甲表示有丝分裂各阶段
题型：填空题 案例分析题
问题：
通过实验研究洋葱根尖细胞有丝分裂过程，得出下图所示的结果，其中图甲表示有丝分裂各阶段细胞核中DNA含量的变化，图乙是有丝分裂显微照片，图丙是洋葱根尖结构示意图。请据图回答下列问题：
可以采用放射性同位素标记技术研究细胞有丝分裂过程中DNA的含量变化，研究中应选择的测量材料丙图的（）部位（填序号）；丙图中①②③④细胞形态不同的根本原因是（）
题型：填空题 案例分析题
| 阅读短文，判断下列句子是否符合短文内容。符合的写 “A”，不符合的写 “B”。 | ||
raising his six children alone. She believed her father had worked very hard to make sure his children grew up healthy and strong. Sonora's father was born in June. So she chose to hold the first Father's Day celebration (庆 祝) on June 19th, 1910. Since 1966 the third Sunday in June has become a national Father's Day in America. In early times, people wore red roses to show respect for fathers who were still living and white flowers for fathers who had died. Today, Americans celebrate Father's Day in many different ways. However the holiday is celebrated, the idea is for children to let their father know that he is loved. | ||
| ( )1. Sonora Dodd thought about starting a Father's Day holiday when she was still a child. ( )2. Sonora Dodd held the first Father's Day celebration in June, 1909. ( )3. After more than 50 years Sonora Dodd's wish came true. ( )4. In the past many different ways were used to show respect for fathers on Father's Day. ( )5. The text mainly tells us something about the history of Father's Day in America. |
