表現(xiàn)型不同的母牛生育出基因型完全相同的牛，產(chǎn)生這一結(jié)果的最可能的原因是（      ）

A．試管動物培養(yǎng)              B．胚胎移植

C．胚胎分割移植              D．用同一公牛配種

單克隆抗體與血清抗體相比，優(yōu)越之處在于   (     )

A．單克隆抗體能夠制成“生物導(dǎo)彈”

B．單克隆抗體可以在體外制備

C．單克隆抗體的特異性強、靈敏度高，產(chǎn)量也大大高于血清抗體

D．單克隆抗體的制備過程簡單

遇海難而漂浮在海面的人，因缺乏淡水，此人                      （  ）

A．血漿滲透壓升高，抗利尿激素增加   B．血漿滲透壓升高，抗利尿激素減少

C．血漿滲透壓降低，抗利尿激素增加   D．血漿滲透壓降低，抗利尿激素減少                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   &n

在悶熱的房間里開會，有的人容易打“哈欠”，其調(diào)節(jié)方式是          （  ）

A．神經(jīng)調(diào)節(jié)     B．體液調(diào)節(jié)     C．神經(jīng)—體液調(diào)節(jié)       D．激素調(diào)節(jié)

生態(tài)系統(tǒng)的營養(yǎng)結(jié)構(gòu)是                                        (   )

A．食物鏈和食物網(wǎng)    B．群落的垂直結(jié)構(gòu)和水平結(jié)構(gòu)

C．群落和無機環(huán)境    D．物質(zhì)循環(huán)和能量流動

細胞核具有什么功能？科學(xué)家通過下列實驗(見下圖)進行探究：①用頭發(fā)將蠑螈的受精卵橫縊為有核和無核的兩半，中間只是很少的細胞質(zhì)相連，結(jié)果無核的一半(a)停止分裂，有核的一半(b)能繼續(xù)分裂；②b部分分裂到16～32個細胞時，將一個細胞核擠入到不能分裂的a部分，結(jié)果a部分開始分裂、分化，進而發(fā)育成胚胎。下列敘述中，不正確的是

A．實驗結(jié)果可以說明細胞核與細胞的分裂、分化有關(guān)

B．實驗①中，b部分細胞屬于對照組，a部分屬于實驗組

C．實驗②中，a部分的操作與實驗①中形成對照

D．實驗說明細胞的壽命與細胞核有關(guān)

下列關(guān)于蛋白質(zhì)和氨基酸的敘述，正確的是

A.具有生物催化作用的酶都是由氨基酸組成的

B.高等動物能合成生命活動所需的20種氨基酸

C.細胞中氨基酸種類和數(shù)量相同的蛋白質(zhì)是同一種蛋白質(zhì)

D.在胚胎發(fā)育過程中，基因選擇性表達，細胞會產(chǎn)生新的蛋白質(zhì)

下列對實驗的相關(guān)敘述，正確的是（    ）

A．鑒定蛋白質(zhì)時，應(yīng)將雙縮脲試劑A液和B液混合以后再加入待檢組織樣液中

B．紙層析法分離葉綠體色素的實驗結(jié)果表明，葉綠b在層析液中溶解度最低

C．可用紫色洋蔥在普通顯微鏡下觀察質(zhì)壁分離、的分布

D．健康人的胃液、唾液和甲狀腺激素3種液體樣本都可以和雙縮脲試劑發(fā)生紫色反應(yīng)

水在生物體內(nèi)是一種良好的溶劑，是各種化學(xué)反應(yīng)的介質(zhì)．下列有關(guān)水的說法不正確的是（   ）

A．水是生物體內(nèi)進行一切生物化學(xué)反應(yīng)的必需條件

B．當人體缺水時，血漿的滲透壓會降低，從而產(chǎn)生渴覺

C．在核糖體上進行的生理過程有水生成

D．休眠或越冬的植物體內(nèi)自由水與結(jié)合水的比值下降

動物細胞工程技術(shù)的基礎(chǔ)是                                               （    ）

A．動物細胞融合                             B．動物細胞核移植

C．動物細胞培養(yǎng)                             D．胚胎移植