定偃侧于人形,正分寸于腧募。(偃)(募)
科学家们用长穗偃麦草(二倍体)与普通小麦(六倍体)杂交培养小麦新品种----小偃麦。相关实验如下,请回答有关问题。小偃麦中有个品种为蓝粒小麦(40W+2E),40W来自普通小麦的染色体,2E表示携带有控制蓝色色素合成基因的一对长穗偃麦草染色体。若丢失了长穗偃麦草的一个染色体,则蓝粒单体小麦(40W+1E),这属于()变异。为了获得白粒小偃麦(一对长穗偃麦草染色体缺少),可将蓝粒单体小麦自交,在减数分裂过程中,产生两种配子,其染色体组成分别为()和(),这两种配子自由结合,产出的后代中白粒小偃麦的染色体组成是()。
染色体数目;20W;20W+1E;40W
Look at this. What’s this in English, do you know? Ah, it’s a photo. Who’s that in the photo? It’s Li Yan. Li Yan is my good frienD. She is a beautiful girl. Who’s that? The boy in black? It’s Jim. He is an English boy. He is very cool. He is my friend, too. We are all in Class 3,Grade 7. I like Jim and Li Yan.
1. What is this? It’s _________.
A. a school B. a friend C. a photo D. an English friend
2. Li Yan is _______.
A. a good boy B. a cool boy C. a beautiful girl D. an English girl
3. What color is Jim in ?
A. Red B. Yellow C. Orange D. Black
4. ---Who’s English? --- ________.
A. I B. Jim C. Li Yan D. Jim and Li Yan
5.--- Who are in the same(同一个) school? --- ______.
A. Jim and Li Yan B. Jim and I C. Li Yan and I D. Jim, Li Yan andI.
1C 2C 3D 4B 5D
Look at this. What’s this in English, do you know? Ah, it’s a photo. Who’s that in the photo? It’s Li Yan. Li Yan is my good frienD. She is a beautiful girl. Who’s that? The boy in black? It’s Jim. He is an English boy. He is very cool. He is my friend, too. We are all in the same school. I like Jim and Li Yan.
( ) 38. What is this? It’s ________.
A. a school B. a friend C. an English friend D. a photo
( )39. Li Yan is ________.
A. a good boy B. a cool boy C. a beautiful girl D. an English girl
( )40. Who are in the same school? ________.
A. Jim and Li Yan B. Jim and I C. Li Yan and I D. Jim, Li Yah andI.
D C D
Look at this. What’s this in English, do you know? Ah, it’s a photo. Who’s that in the photo? It’s Li Yan. Li Yan is my good frienD. She is a beautiful girl. She is ChinesE. Who’s that? The boy in black? It’s Jim. He is an English boy. He is very cool. He is my friend, too. We are all in the same school. I like Jim and Li Yan. Jim often teaches Li Yan and me English, and we often teach him ChinesE.
( )51. What is this? It’s
A. a school B. a friend C. a photo D. an English friend
( ) 52. Li Yan is .
A. a good boy B. a cool boy C. a Chinese girl D. an English girl
( ) 53. What color is Jim in? .
A. Red B. Yellow C. Orange D. Black
( ) 54. Who’s English? .
A. I B. Jim C. Li Yan D. Jim and Li Yan
( ) 55. Who are in the same school? .
A. Jim and Li Yan B. Jim and I C. Li Yan and I D. Jim, Li Yan andI.
Hello.Is that WangYan ? Yes ,______
A:This is Wang Yan . B: Who are you ? C:I.’m speaking . D:I.’m Wang Yan
1.下列各组词语中,加点字读音全部正确的—项是
A: 露骨(lu) 诡对(gui) 吮血 fc(shun) 前后合偃 (yan) B: 畏葸(si) 押解 (jie) 料峭 (qiao) 咄咄逼人(duo) C: 孝悌(di) 聒噪(guo) 即兴(xing) 锲而不舍(qie) D: 孱弱 (can) 宫绦 (tiao) 粗犷(guang) 囿于成见(you)
No sooner ________ stepped on the stage than the audience broke into thunderous applausE.
A: had Mo Yan B: Mo Yan had C: has Mo Yan D: Mo Yan has
科学家们用长穗偃麦草(二倍体)与普通小麦(六倍体)杂交培育小麦新品种——小偃麦。相关的实验如下,请回答有关问题:
(1)长穗偃麦草与普通小麦杂交,F1体细胞中的染色体组数为____。长穗偃麦草与普通小麦杂交所得的F1不育,其原因是____________________,可用________处理F1幼苗,获得可育的小偃麦。
(2)小偃麦中有个品种为蓝粒小麦(40W+2E),40W表示来自普通小麦的染色体,2E表示携带有控制蓝色色素合成基因的1对长穗偃麦草染色体。若丢失了长穗偃麦草的一个染色体则成为蓝粒单体小麦(40W+1E),这属于________变异。为了获得白粒小偃麦(1对长穗偃麦草染色体缺失),可将蓝粒单体小麦自交,在减数分裂过程中,产生两种配子,其染色体组成分别为________,这两种配子自由结合,产生的后代中自粒小偃麦的染色体组成是________。
(3)为了确定白粒小偃麦的染色体组成,需要做细胞学实验进行鉴定。取该小偃麦的____作实验材料,制成临时装片进行观察,其中____期的细胞染色体最清晰。
(1)4,无同源染色体、不能形成正常配子(减数分裂时联合紊乱),秋水仙素
(2)染色体数目,20W和20W+1E,40W
(3)根尖或芽尖(答分生区、生长点不得分),有丝分裂中(期)
科学家们用长穗偃麦草(二倍体)与普通小麦(六倍体)杂交培育小麦新品种——小偃麦。相关的实验如下,请回答有关问题:
(1)长穗偃麦草与普通小麦杂交,F1体细胞中的染色体组数为 。长穗偃麦草与普通小麦杂交所得的F1不育,其原因是 ,可用 处理F1幼苗,获得可育的小偃麦。
(2)小偃麦中有个品种为蓝粒小麦(40W+2E),40W表示来自普通小麦的染色体,2E表示携带有控制蓝色色素合成基因的1对长穗偃麦草染色体。若丢失了长穗偃麦草的一个染色体则成为蓝粒单体小麦(40W+1E),这属于 变异。为了获得白粒小偃麦(1对长穗偃麦草染色体缺失),可将蓝粒单体小麦自交,在减数分裂过程中,产生两种配子,其染色体组成分别为 ,这两种配子自由结合,产生的后代中自粒小偃麦的染色体组成是 。
(3)为了确定白粒小偃麦的染色体组成,需要做细胞学实验进行鉴定。取该小偃麦的 作实验材料,制成临时装片进行观察,其中 期的细胞染色体最清晰。
(1)4 2分
无同源染色体,不能形成正常的配子(减数分裂时联会紊乱) 2分
秋水仙素 2分
(2)染色体数目 2分
20W和20W+1E 2分
40W 2分
(3)根据或芽尖(答“分生区、生长点”不得分) 2分
有丝分裂中期 2分