题干

如图为人类某种单基因遗传病系谱图,Ⅱ﹣4为患者,则下列相关叙述合理的是(  )

A:该病一定属于常染色体隐性遗传病

B:Ⅱ﹣3是携带者的概率为 12

C:若Ⅰ﹣2不携带致病基因,则Ⅰ﹣1的一个初级卵母细胞中含有4个致病基因

D:若Ⅰ﹣2携带致病基因,则Ⅰ﹣1和Ⅰ﹣2再生一个患病男孩的概率为 18

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答案(点此获取答案解析)

D

同类题1

阅读理解

    My transportation was unexpectedly smooth and I arrived at the meeting half an hour earlier. I kept my eyes on the restaurant door. Several customers entered, but not my friend. At 6:00 pm, she sent me a text message:“Urgent work to finish. Will be 20 minutes late.”

I had left my book in the office, so I spent the time thinking of my experiences of being late in China. On my first visit in 1985, punctuality was deeply rooted in the Chinese hearts. There were no traffic jams then.

    As a teacher in Canada, I always insisted on punctuality. I would open the classroom door to a late student for the first time and the second, but not the third. During the six years I worked for CCTV, I had a Chinese friend whom I often saw at lunch time, or after work. We used to meet at the subway station nearby. He was always late by 10-20 minutes. To myquestion, “You were busy?” he would surprisingly answer, “ No.” Once I asked him to check the clock in his office, he smiled.

    In March 2015, I got permanent residence (居住权) in China.The ceremony was scheduled for 9:00 am at the Public Security Bureau on the Second Ring Road. I told my driver I had to get there by 8: 40 am. “No problem,”he replied. But he thought he had time to drop someone off at the airport before picking me up. I desperately waited for him. Then, to rub salt into my wound, he had to stop at the exit of a gas station. Finally, I entered the room at 9:07 am ── the last guest to arrive!

同类题4

阅读下面的文言文,完成下列小题。

    韦睿,字怀文,京兆杜陵人也。事继母以孝闻。睿内兄王橙、姨弟杜恽,并有乡里盛名。伯父祖征谓睿曰:“汝自谓何如橙、恽?”睿谦不敢对。祖征曰:“汝文章或小减,学识当过之;而干国家,成功业,皆莫汝逮也。”

    后东宫建,迁太子右卫率,出为辅国将军。四年,王师北伐,诏睿都督众军。睿遣长史王超宗、梁郡太守冯道根攻魏小岘城,未能拔。睿巡行围栅,魏城中忽出数百人陈于门外,睿欲击之,诸将皆曰:“向本来,未有战备,徐还授甲,可进耳。”睿曰:“不然。。魏城中二千余人,闭门坚守,足以自保,无故出入于外,必其骁勇也,若能挫之,其城自拔。”众犹迟凝,睿指其节曰:“朝廷授此,非,韦睿之法,不可犯也。”乃进兵。士皆殊死战,魏军果败走,急攻之,中宿而城拔。

    睿于故旧,无所遗惜,士大夫年七十以上者,多与假板县令,乡里甚怀之。十五年,拜表仕,优诏不许。十七年,征散骑常侍、护军将军,寻给鼓吹一部,入直殿省。居朝廷,恂恂未尝忤视,高祖甚礼敬之。性慈爱,睿抚孤兄子过于己子。历官所得禄赐,皆散之亲故,家无余财。后为护军居家无事慕万石陆贾之为人因画之于壁以自玩。时虽老,暇日犹诸儿以学。第三子棱,尤明经史,世称其洽闻,睿每坐,棱使说书,其所发植,棱犹弗之逮也。高祖方锐意释氏,天下成从风而化。睿位居大臣,不欲与俗俯仰,所行略如他日。

(《梁书》卷十二列传第六)

【注释】①围栅:营寨。②假板:未经朝廷而对低级官吏进行任命。受任命者称假板官。③释氏:佛教