皮皮学，免费搜题
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【单选题】
生物地球化学循环是指：组成生物体的基本元素（ ）
A.
．在陆地生态系统中的物质循环和能量流动的复杂过程
B.
．在能量流经生态系统各营养级时的逐级递减的全过程
C.
．在组成生态系统的生物群落和生物体内的反复循环运动
D.
．在生物圈的生物群落和无机环境中的反复循环运动
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举一反三
【单选题】既是抗原又是抗体的物质是( )
A.
类毒素
B.
干扰素
C.
生理盐水
D.
细菌外毒素
E.
破伤风抗毒素
查看完整题目与答案
【单选题】What is the common factor of the three sounds: p, k, t?
A.
voiceless
B.
spread
C.
voiced
D.
nasal
查看完整题目与答案
【单选题】既是 抗原又是抗体的物质是
A.
细菌外毒素
B.
类毒素
C.
细菌内毒素
D.
动物免疫血清
E.
青霉素
查看完整题目与答案
【单选题】----Ms.Carol is not in.Can I take a message? ----( )
A.
Well,I'd prefer to call later.
B.
You'd better not.
C.
Thank you all the same.
D.
That's all right.
查看完整题目与答案
【单选题】对人体既是抗原又是抗体的物质是
A.
细菌外毒素
B.
马抗破伤风血清
C.
具有免疫活性的淋巴细胞
D.
HLA
E.
干扰素
查看完整题目与答案
【简答题】What is the common factor of the three sounds:[p] [t] [k] ?A. Voiceless. B. Voiced. C. Spread. D. Nasal.
查看完整题目与答案
【多选题】What are the function of the three different nuclear RNA p olymerases in eukaryotic cells?
A.
Eukaryotes have three RNA polymerases, designated I, II, and III, which are distinct complexes but have certain subunits in common. Each polymerase has a specific function and is recruited to a specific promoter sequence.
B.
RNA polymerase I (Pol I) is responsible for the synthesis of only one type of RNA, a transcript called preribosomal RNA (or pre-rRNA), which contains the precursor for the 18S, 5.8S, and 28S rRNAs. Pol I promoters differ greatly in sequence from one species to another.
C.
The principal function of RNA polymerase II (Pol II) is synthesis of mRNAs and some specialized RNAs. This enzyme can recognize thousands of promoters that vary greatly in sequence. Some Pol II promoters have a few sequence features in common, including a TATA box (eukaryotic consensus sequence TATA(A/T)A(A/T)(A/G)) near base pair −30 and an Inr sequence (initiator) near the RNA start site at +1. However, such promoters are in the minority, and elaborate interactions with regulatory proteins guide Pol II function at many promoters that lack these features.
D.
RNA polymerase III (Pol III) makes tRNAs, the 5S rRNA, and some other small specialized RNAs. The promoters recognized by Pol III are well characterized. Some of the sequences required for the regulated initiation of transcription by Pol III are located within the gene itself, whereas others are in more conventional locations upstream of the RNA start site.
查看完整题目与答案
【单选题】对人体既是抗原又是抗体的物质是
A.
细菌外毒素
B.
马抗破伤风血清
C.
类毒素
D.
HLA
E.
干扰素
查看完整题目与答案
【单选题】For a large pane one flight attendant per ______ passenger seat is needed.
A.
50
B.
100
C.
150.
D.
200
查看完整题目与答案
【单选题】What time will the staff meeting begin?
A.
At three o'clock.
B.
At half past three.
C.
At half past four.
查看完整题目与答案
相关题目：
【单选题】既是抗原又是抗体的物质是( )
A.
类毒素
B.
干扰素
C.
生理盐水
D.
细菌外毒素
E.
破伤风抗毒素
查看完整题目与答案
【单选题】What is the common factor of the three sounds: p, k, t?
A.
voiceless
B.
spread
C.
voiced
D.
nasal
查看完整题目与答案
【单选题】既是 抗原又是抗体的物质是
A.
细菌外毒素
B.
类毒素
C.
细菌内毒素
D.
动物免疫血清
E.
青霉素
查看完整题目与答案
【单选题】----Ms.Carol is not in.Can I take a message? ----( )
A.
Well,I'd prefer to call later.
B.
You'd better not.
C.
Thank you all the same.
D.
That's all right.
查看完整题目与答案
【单选题】对人体既是抗原又是抗体的物质是
A.
细菌外毒素
B.
马抗破伤风血清
C.
具有免疫活性的淋巴细胞
D.
HLA
E.
干扰素
查看完整题目与答案
【简答题】What is the common factor of the three sounds:[p] [t] [k] ?A. Voiceless. B. Voiced. C. Spread. D. Nasal.
查看完整题目与答案
【多选题】What are the function of the three different nuclear RNA p olymerases in eukaryotic cells?
A.
Eukaryotes have three RNA polymerases, designated I, II, and III, which are distinct complexes but have certain subunits in common. Each polymerase has a specific function and is recruited to a specific promoter sequence.
B.
RNA polymerase I (Pol I) is responsible for the synthesis of only one type of RNA, a transcript called preribosomal RNA (or pre-rRNA), which contains the precursor for the 18S, 5.8S, and 28S rRNAs. Pol I promoters differ greatly in sequence from one species to another.
C.
The principal function of RNA polymerase II (Pol II) is synthesis of mRNAs and some specialized RNAs. This enzyme can recognize thousands of promoters that vary greatly in sequence. Some Pol II promoters have a few sequence features in common, including a TATA box (eukaryotic consensus sequence TATA(A/T)A(A/T)(A/G)) near base pair −30 and an Inr sequence (initiator) near the RNA start site at +1. However, such promoters are in the minority, and elaborate interactions with regulatory proteins guide Pol II function at many promoters that lack these features.
D.
RNA polymerase III (Pol III) makes tRNAs, the 5S rRNA, and some other small specialized RNAs. The promoters recognized by Pol III are well characterized. Some of the sequences required for the regulated initiation of transcription by Pol III are located within the gene itself, whereas others are in more conventional locations upstream of the RNA start site.
查看完整题目与答案
【单选题】对人体既是抗原又是抗体的物质是
A.
细菌外毒素
B.
马抗破伤风血清
C.
类毒素
D.
HLA
E.
干扰素
查看完整题目与答案
【单选题】For a large pane one flight attendant per ______ passenger seat is needed.
A.
50
B.
100
C.
150.
D.
200
查看完整题目与答案
【单选题】What time will the staff meeting begin?
A.
At three o'clock.
B.
At half past three.
C.
At half past four.
查看完整题目与答案