题干

下列关于细胞结构和功能的叙述中,不正确的是                                (   )
①精子细胞、神经细胞、根尖分生区细胞不是都有细胞周期,但化学成分不断更新
②硝化细菌、霉菌、水绵的细胞都含有核糖体、DNA和RNA
③能进行光合作用的细胞一定含有叶绿体 
④抑制细胞膜上载体活性或影响线粒体功能的毒素,都会阻碍根细胞吸收矿质离子 
⑤性激素的合成与内质网有关 
⑥人体内不再分裂的体细胞中共有46个DNA分子 
⑦在一个细胞周期中,T和U两种碱基被大量利用时,细胞一定处于分裂间期                    

A:③⑥

B:②③⑥

C:②③⑤

D:③

上一题 下一题 0.0难度 选择题 更新时间:2014-12-12 09:27:16

答案(点此获取答案解析)

A

同类题1

阅读理解

Mini Book Excerpts (节选)

    Biography

    When Salinger learned that a car park was to be built on the land, the middle-aged writer was shocked and quickly bought the neighboring area to protect it… The townspeople never forgot the rescue and came to help their most famous neighbor.

    J. D. Salinger: A Life by Kenneth Slawenski (Random House, $ 27)

    Mystery

    “You're a smart boy. Benny's death was no accident, and you're the only one who saw it happen. Do you think the murderer should get away with it?” The boy was staring stubbornly at his lap again.

    A thought suddenly occurred to Annika, “Did you... You recognized the man in the car, didn't you?”

    The boy hesitated, twisting his fingers. “Maybe,” he said quietly.

    Red Wolf by Liza Marklund (Atria Books, $ 25.99)

    Short Stories

    She wants to say to him what she has learned, none of it in class. Some women are born stupid, and some women are too smart for their own good. Some women are born to give, and some women only know how to take. Some women learn who they want to be from their mothers, some who they don't want to be. Some mothers suffer so their daughters won't. Some mothers suffer so their daughters won't.

    You Are Free by Danzy Senna (Riverhead Books, $ 15)

    Humor

    Do your kids like to have fun? Come to Fun Times! Do you like to watch your kids having fun? Bring them to Fun Times! Fun Times's “amusement cycling” is the most fun you can have in the United States right now. Why spend thousands of dollars flying to Disney World when you can spend less than half to that within a day's drive in most cities?

    Happy And Other Bad Thoughts by Larry Doyle (Ecco, $ 14.99)