第9题: [单项选择]下列均属于单倍体的一组是()①蜜蜂中的雄蜂②香蕉③无子西瓜④具有三个染色体组的普通小麦⑤具有一个染色体组的玉米⑥具有两个染色体组的马铃薯 A. ①④⑤⑥ B. ②③④⑤ C. ①③④⑥ D. ①②④⑥ 参考答案:A 答案解析:试题分析:单倍体是由配子直接发育而来的个体。蜜蜂中的雄蜂是由蜂王的卵细胞直接发育而来的,属于单倍体;香蕉是三倍体,不是单倍体;无子西瓜是多倍体育种形成的,属于多倍体;普通小麦是六倍体,因此具有三个染色
第27题: [单项选择]Passage Three Questions 32 to 35 are based on the passage you have just heard. A. They are big and capable of attacking. B. They serve their owners as friends and guards. C. They make most people afraid. D. They are easy to take care of. 参考答案:B 答案解析:[听力原文] Why are many families fond of the German shepherd