题干

番茄中红果(R)对黄果(r)是显性,如果把黄果植株的花粉授到红果植株的柱头上,所结果实的颜色和果实中种子胚的基因型分别是(   )

A:红、Rr或rr

B:黄或红、rr

C:红、Rr

D:橙黄、Rr

上一题 下一题 0.0难度 选择题 更新时间:2016-04-29 02:51:58

答案(点此获取答案解析)

A

同类题2

阅读《一双皮鞋的秘密》,完成下列小题。

      ①我上高中的时候,班里大多数同学都买了皮鞋,我也想买一双。

      ②星期六回家, 我对妈妈说了。妈妈半天没说话,只是盯着我。好久,她才说,非买不可吗?我没有说话,却点了点头。妈妈说,你快要交学费了吧?我又点了点头。妈妈又说,你的学费还没攒够呢!我听了没说话,把头转到了一边。妈妈说,你爸爸在地里刨葱,你去看看吧。

      ③我去了地里,爸爸正在刨葱。见我不说话,爸爸问,怎么了?我还是不说话。爸爸就不问了。那天的天气很好,可我却觉得很闷,头就像被谁用棍子打了一下。过了一会儿,妈妈也到了地里。她把我想要皮鞋的事给爸爸说了。爸爸听了,过了好大一会儿才说,晚几天买不行吗?我不说话,我想星期一上学的时候就穿上新皮鞋。可我说不出口,我知道我的家境很穷。

      ④爸爸说,你想要皮鞋,行,你肯下力气吗?我说,肯下力气。爸爸说,邹县的葱比咱这儿贵好几分钱,只是路太远了,我一个人拉排车怕拉不到。我当时就说,我帮你拉。

      ⑤邹县离我们这儿有七十里路,我和爸爸吃过晚饭,就拉着一千多斤的葱上路了。刚开始,我觉得还行,没怎么费力。大约走了有二十里路,就觉得浑身上下酸酸的,排车的轮子好像坏了。我和爸爸吃力地前进着。爸爸说,你能坚持到邹县吗?我咬了咬牙,说,能。爸爸就不再说什么了。

      ⑥晚上没有月光,只有几颗星星在天空眨着眼。有露水从天上落下来,打湿了我和爸爸的头发。晚上已经很冷了,可我们身上却流着汗。为了一双皮鞋,我豁出去了。

      ⑦大概走了一半的路程,我就走不动了。三十多里路,我们走了四个小时,但还有四个小时的路呢!我说,邹县可真远。爸爸说,不近。我说,咱歇一会儿吧。爸爸说,你不想要皮鞋就歇一会儿吧。我说,歇一会儿就买不成皮鞋了?爸爸说,咱早到一会儿可能卖个好价钱,晚到一会儿可能就把你的皮鞋给耽误了。

      ⑧我说,那咱赶路吧。爸爸说,咱一口气赶到。我咬了咬牙说,行。

      ⑨那天葱卖得很好,一斤比我们那里多卖八分钱,一千多斤就多卖了一百多块钱。我心里很高兴,我的皮鞋有希望了。

      ⑩一回到家,我就躺在了床上。我一夜没合眼,累坏了。待我醒来时,爸爸把一双皮鞋递到了我手里,我心里很高兴。妈妈说,花了一百多块呢!

      ⑪星期一,我就穿着皮鞋去了学校。有个眼尖的同学说,你的皮鞋不是皮的。我不信。同学给我指了出来,我的心当时就凉了。

      ⑫爸爸被人骗了,那可是我们俩的力气钱啊!说真的,我当时沮丧极了。后来我回家,爸爸问我,怎么没穿皮鞋?我说,我得省着穿。爸爸笑着说,知道省就好。爸爸说,你要想穿上名牌皮鞋就得好好学习。

      ⑬我一直保存着那双皮鞋。我怎么也忘不了为了一双皮鞋,我和爸爸拉着一千多斤的葱到七十里开外的邹县去卖。我和爸爸辛辛苦苦多卖的钱,被卖皮鞋的人给骗去了。至今我都没有给爸爸说那是双假皮鞋,我不想让爸爸伤心。如今我已结婚生子,我不再为了一双皮鞋而发愁。可我怎么也忘不了那双皮鞋,就是那双皮鞋让我知道了做人的艰辛。那双皮鞋怕是要陪伴我一辈子了。

      ⑭一天,我陪爸妈吃饭。妈妈说,你知道吗,多年前的那双皮鞋是革的。我说,我穿上皮鞋到了学校就知道了。妈妈说,可你没说啊。我说,我知道那双鞋比真皮鞋还贵。

     ⑮爸爸突然说,有个秘密你们都不知道,当年我没有被骗。我和妈妈一听,都愣了。爸爸继续说,我去给你买皮鞋时,在路上遇见了一个病危的老太太,我把钱给她了。我想皮鞋真假都一样穿,可人的命就只有一条。

      ⑯爸爸的头发已经花白了,他的背也已经驼了,但我却忽然发现,爸爸比以前任何时候都高大。在他面前,我只能仰望,一直到永远。

同类题3

任务型阅读

    US City Bans Texting while Walking

    Parents usually teach their children how to cross the street safely, by looking both ways for cars. But do they also teach them to put away their cell phones?

    The city of Honolulu, Hawaii wants everyone to learn that lesson____Beginning on October 24, you could be fined from $15 to $99 if you step into a Honolulu street while looking at your phone. Honolulu is the first major U. S. city to ban what is called "distracted (分散注意) walking. " It recently passed a law in a seven to two vote. The law says; “No pedestrian shall cross a street or highway while viewing a mobile electronic device. "____

    The law's creators hope it will lower the number of people hit and killed by cars in the city. Mayor Kirk Caldwell told Reuters news agency, "We hold the unfortunate distinction (区别) of being a major city with more pedestrians being hit in crosswalks, particularly our elders, than almost any other city in the country. "

    The law includes all electronic devices with screens: cell phones, tables, gaming devices, digital cameras and laptop computers____Pedestrians may use such devices in the street to call emergency services and rescue workers, such as firefighters and police officers.

    ____The Governors Highway Safety Association, or GHSA, says pedestrian deaths in the United States increase 25 percent between 2010 and 2015. That trend continued in 2016 with the number of pedestrian deaths rising to almost 6000, 11% higher than in 2015.

    If you still want to text while walking, you could avoid being fined in Honolulu (and be safer, in general) by using a voice-controlled digital(数字的) assistant such as Siri or Google Assistant____

A. The law does permit an exception.

B. Or you could just wait until you are again, safely, off the street.

C. You will be sentenced to prison while using cell phones in the street.

D. Pedestrian deaths have been increasing as the use of cell phones rises.

E. Texting while crossing the street will soon be banned in the city.

F. The law permits people to watch TV while crossing the street.

G. In other words, do not look at a screen when you cross the street or you could be fined.