分子生物学试卷

1 名词解释 1、DNA cloning is a technique for reproducing DNA fragments.

2、Gene library: a collection of different DNA sequence from an organism, each of which has been cloned into a vector for ease of purification, storage and analysis. 3、Subcloning is a basic molecular biology procedure used to move inserts from one vector to another. 4、PCR is to used to amplify a sequence of DNA using a pair of oligo- nucleotide primers each complementary to one end of the DNA target sequence.

填空 1、The methods make sure that the mRNA is not degraded is Translating the mRNA and Analysis the mRNAs by gel elctrophoresis 2、The recombinant molecules are either packaged or transformed to create the cDNA library. 3、Two main methods of DNA sequencing is chemical method and enzymic method

选择 1、Which of the following is an imino acid? ( ) A praline B hydroxylysine C tryptophan D histidine

2 Edman degradation sequences peptides ( ) A using a cDNA sequence B according to their mssses C from the C-terminus to the N-terminus D from the N-terminus to the C-terminus

3 The sequence 5′-AGTCTGACT-3′ in DNA is equivalent to which sequence i8n RNA ? A 5′-AGUCUGACU-3′ B 5′-UGTCTGUTC-3′ C 5′-UCAGUCUGA--3′ D 5′-AGUCAGACU-3′

4 The essential initiator protein at the E.coli origin of replication is( ) A DnaA B DnaB C DnaC D DnaE

5 In eukaryotes ,euchromatin replicates predominannnnnntly ( )

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A in early S-phase B in mid S-phase C in late S-phase D in G2-phase

6 The presence of a plasmid in a bacterial culture is usually determined by ( ) A blue-white screening B growth in the present of an antibiotic C arestriction enzyme digest D agarose gel electrophoresis

7 Transformation is ( ) A the take-up of a plasmid into a bacterium B the expression of a gene in a bacterium C the take-up of a bacteriphage into a bacterium D the isolation of a plasmid from a bacterium

8 In agarose gel electrophoresis ( ) A DNA migrates towards the negative electrode B supercoiled plamids migrate slower than their nicked counterparts C larger molecules migrate faster than smaller molecules D ethidium bromide can be used to visualize the DNA

9 Blue-white selection is used ( ) A TO TEST FOR THE PRESENCE OF A PLASMID IN BACTERIA B to reveal the identity of a cloned DNA fragment C to express the product of a cloned gene D to test for the presence of a cloned insert in a plasmid

10 Which one of these statement about the applications of gene cloning is false?( ) A large amounts of recombinant protein can be produced bu gene cloning B DNA fingerpring is used to detect protreins bound to DNA C cloned gene can be used to detect carriers of disease-causing gene D gene therapy attempts to correct a disorder bu delivering a gond copy of a gne to a paitien

11 Which ribonucleases are involved in producing mature tRNA in E.coli?( ) A RNases A,D,E,and F B RNases D,E,F,and H C RNases D,E,Fand P D RNases A,D,H and p 12 which of the following list of features correctly apply to the gentic code ?( ) A triplet, degenerate,nearly universal,comma-less,nonoverlapping B triplet, universal, comma-less, degenerate, nonoverlapping C overlapping ,triplet, comma-less, degenerate ,nearly universal

Doverlapping,comma-less,nondegenerate,nearly universal ,triplet, 简答 3

四、What are the essential steps in DNA cloning? 1、 DNA recombination. The DNA fragment to be cloned is inserted into a vector 2、 Transformation. The recombinant DNA enters into the host cell and proliferates. It is called "transformation" because the function of the host cell may be altered. 3、 Selective amplification. A specific antibiotic is added to kill E. coli without any protection. The transformed E. coli is protected by the antibiotic-resistance gene whose product can inactivate the specific antibiotic. 4、 Isolation of desired DNA clones.

• 一、What are the basic steps for construction of cDNA library? – Isolate mRNA – Then, conduct reverse transcription – Insert recombinant fragment into vectors and get clones.

五、What are the properties of plasmid? • Plasmids are (typically) circular double-stranded DNA molecules • Capable of autonomous replication. • They usually occur in bacteria, sometimes in eukaryotic organisms • Their size varies from 1 to over 400 kbp. • There are normally from one copy, for large plasmids, to hundreds of copies of the same plasmid present in a single cell. • Can used as a vector for gene insertion or genetic engineering. Multiple cloning site (MCS), antibiotic gene(s), ori (origin of replication)