第二章 单元测试

1、判断题：
Tm is directly related to the GC content of DNA and ionic strength.
选项：
A:错
B:对
答案: 【对】

2、判断题：
rRNA is the site for protein biosynthesis.
选项：
A:错
B:对
答案: 【错】

3、单选题：
In a DNA molecule, if the molar ratio of A is 17.2%, the molar ratio of C should be ( )
选项：
A:65.6％
B:17.2％
C:67.2％
D:32.8％
E:50.3%
答案: 【32.8％】

4、单选题：
The key part of DNA molecule to store and transmit genetic information is ( )
选项：
A:base sequence
B:pentose phosphate skeleton
C:base rotation angle
D:Pentose conformation
E:phosphate diester bond
答案: 【base sequence】

5、单选题：
The force to maintain the lateral stability of DNA double helix is ( )
选项：
A:disulfide bond
B:phosphodiester bond
C:Base packing force
D:Internal screw drainage
E:hydrogen bond between base pairs
答案: 【hydrogen bond between base pairs】

6、单选题：
What's wrong with nucleic acid hybridization ( )
选项：
A:DNA single strand can hybridize with RNA strand with almost the same complementary base
B:RNA DNA hybrid chain can be synthesized by reverse transcription using mRNA as template
C:Using molecular hybridization, the target gene can be fished from gene library
D:mRNA can be hybridized with the encoded polypeptide chain
E:Two single stranded DNA from different sources can be hybridized as long as some bases are complementary
答案: 【mRNA can be hybridized with the encoded polypeptide chain】

7、多选题：
The changes in DNA denaturation are: ( )
选项：
A:covalent bond fracture
B:Viscosity increase
C:Hydrogen chain breaking and double helix structure breaking between chains
D:hyperchromic effect
答案: 【Hydrogen chain breaking and double helix structure breaking between chains;
hyperchromic effect】

8、多选题：
The histones that make up the core particle of nucleosome are ( )
选项：
A:H2A
B:H4
C:H1
D:H2B
E:H3
答案: 【H2A;
H4;
H2B;
H3】

9、多选题：
As for the description of rRNA, it is correct to ( )
选项：
A:Containing more rare bases
B:Large and small subunits that can combine with proteins to form ribosomes
C:No secondary structure
D:Shortest half-life
E:It's the most abundant RNA in the cell
答案: 【Large and small subunits that can combine with proteins to form ribosomes;
It's the most abundant RNA in the cell】

10、多选题：
The biological functions of nucleotides in vivo include ( )
选项：
A:Raw materials for nucleic acid synthesis in vivo
B:As cytoskeleton
C:Some nucleotides can be used as second messengers of hormones
D:Some nucleotides are the direct energy suppliers in the organism
E:Some nucleotides are allosteric effectors of allosteric enzymes
答案: 【Raw materials for nucleic acid synthesis in vivo;
Some nucleotides can be used as second messengers of hormones;
Some nucleotides are the direct energy suppliers in the organism;
Some nucleotides are allosteric effectors of allosteric enzymes】