题干

下列有关受精作用的叙述,不正确的是(   )

A:受精卵中全部的遗传物质一半来自精子

B:受精时,精子的细胞核和卵子的细胞核融合

C:合子中的染色体数和本物种体细胞中染色体数一致

D:合子中的染色体一半来自父方,一半来自母方

上一题 下一题 0.0难度 选择题 更新时间:2018-08-15 10:02:45

答案(点此获取答案解析)

A

同类题1

任务型阅读

    In fact there are lots of videos of school bullying online every year. We feel angry with the bullies and sorry for the victims in fights and blackmails. Some middle schools and primary schools in some far counties and villages are the worst-hit parts. Nearly half the victims of bullying in middle schools choose to stay silent rather than ask for help or ways to solve the problem, China Youth Daily reported.

    There is a study on junior middle school bullying made by the China Women's University. It showed that 48.9 percent of the students never asked for help after being bullied. And the study also told us 52.6 percent kept silent because they were afraid of “losing face among schoolmates”.

    The China Youth and Children Research Center made a survey of 5,864 primary and middle school percent of students suffered bullying, while 6.1 percent were often bullied by senior schoolmates.

    Cases of violence between boys and girls totaled 85 percent of all school bullying, the report said. Violence between girls accounted for as much as 32.5percent of the total. Unlike direct arguments usually seen between boys, the violence between girls more often took the form of insults, which terribly caused victims have strong feelings, it was added.

    A study published by the Beijing High People's Court showed that 68 percent of offenders attacked their schoolmates in a cruel manner and nearly 60 percent of school violence cases were caused by small matters, Legal Daily said.

    Earlier, Tang Jun of Renmin University of China told reporters that the social risks of school bullying have been given too little care. We should train our teachers to deal with school bullying, improve their skills of preventing it, and help the victim students to recover physically and mentally. At the same time, students and their parents should know the school's rules about bullying and what they should do if it happens. Second, children should be taught to stand up for themselves. They should try to solve problems by talking them out. Children should tell someone if they are being picked on. Third, parents should look for warning signs of bullying. We must pay more attention to it and try our best to solve it.

同类题5

比较阅读下面的文字,回答问题。
                                                                                              (一)
         山泉作娇儿之态,泉声则是孩子如铃的笑语。受泉声的感染,鼎湖山年轻了许多,山径之幽曲,竹木之青翠,都透着一股童稚的生气,使进山之人如入清澈透明的境界,身心了无杂尘,陡觉轻快。行至半山,有一补山亭。亭已破旧,无可驻目之处,惟亭内一副楹联“到此已无尘半点,上来更有碧千寻”,深得此中精神,令人点头会意。
        站在亭前望去,满眼确是一片浓碧。远近高低,树木枝缠藤绕,密不分株,沉甸甸的湿绿,犹如大海的波浪,一层一层,直向山顶推去。就连脚下盘旋曲折的石径,也印满苔痕,点点鲜绿。踩着潮润柔滑的石阶,小心翼翼,拾级而上。越向高处,树越密,绿意越浓,泉影越不可寻,而泉声越发悦耳。怅惘间,忽闻云中传来钟声,顿时,山鸣谷应,悠悠扬扬。安详厚重的钟声和欢快清亮的泉声,在雨后宁静的暮色中,相互应答着,像是老人扶杖立于门前,召唤着嬉戏忘返的孩子。(节选自谢大光《鼎湖山听泉》)
                                                                                             (二)
        如果遇上大的障碍,水就嘟嘟哝哝地仿佛表示不满,这嘟哝声和从障碍上飞溅过去的声音,老远就可听见。然而这不是示弱,不是诉怨,也不是绝望,这些人类的感情,水是毫无所知的。每一条小溪都深信自己会到达自由的水域,即使遇上像尼尔布鲁士峰一样的山,也会将它劈开,早晚会到达……
水流在克制的嘟哝声中稳稳地流淌着,它们兴奋得不能不互相呼唤:许多支有力的水流都流到了一起,汇合成了一股大的水流,彼此间又说话又呼唤——这是所有来到一起又要分开的水流在打招呼呢。(节选自普里什文《林中小溪》)