浙江万里学院《基因工程》试题（五）参考答案
I. Definition:
1. Genes and Genome: Gene expression refers to a protein or functional RNA, the
basic unit; genome: is a complete set of genes contained in biological.
2. Cos-Plasmid: Cosby l-DNA plasmid that contains cos areas at both ends of plasmid
As the λ-DNA packaging proteins recognize only the sticky at the end of a short
sequence of cos zone. Will this DNA together with the plasmid, the recombinant
plasmid.
3. Bactericidal peptides: the ability to play the role of bactericidal peptides, and many
insects have such peptides, can destroy the bacteria cell membrane, causing ion
channels, leading to leakage of cellular inclusions.
4. Satellite DNA: tonsure in CsCl isopycnic ultra-centrifugation, the emergence of a
peak, and 1 or 2 small peaks, this small peak to the peak in terms of peak especially
like the satellite, so called satellite DNA.
5. Single-strand binding protein: one which can be with single-stranded DNA binding
proteins to tetrameric form and single-stranded DNA binding, since maintaining the
existence of single-chain role.
6. Degenerate codes: from more than one code encoding the same amino acid is called
a degenerate (degeneracy), corresponding to the same amino acid code is called
synonymous code or code degeneracy.
7. Reverse mutation: mutation phenotype there are two types, one type is forward
mutation from the wild type to mutant, and the other is a mutant to the wild-type
known as the reverse mutation.
8. Telomerase: a RNA-protein complex, which can be its RNA as a template by
reverse transcription process to extend the right end of the DNA chain
9. Code of the swing: In the code and anti-code pair, the first two pairs of strict
observance of the principle of base pairing, the third base pairs have a certain degree
of freedom.
10. Temporal gene: only a certain period in development can be expressed by a
number of specific genes.
II. Fill-in:
1. (AP) 2. (Thymus) (pyrimidine dimer)
3. (RNA)
4. (CGU)
5. (Site-specific), (4,6,8 months bp), (palindromic sequences of DNA) 6. (Repression
mechanism) (weakening of the mechanism) 7. (Metabolites on the regulation of gene
activity), (weakening of the child on the impact of gene activity), (degradation
products of the regulation of gene activity), (bacteria emergency response) 8. (Strict
type), (loose type) 9. (Zinc finger motif); (helix turn helix motif); (helix-loop-helix
motif); (leucine zipper motif)
III. Multiple-choice:
1. (B) 2. (B) 3. (C) 4. (B) 5. (D) 6. (D) 7. (A) 8. (B) 9. (B) 10. (C)
IV True or False:
1. (×) 2. (√) 3. (×) 4. (×) 5. (×) 6. (√) 7. (×) 8. (√) 9. (√) 10. (×)
V. Short Answer :
1. Design an experiment to prove that DNA replication is semi-conservative
conducted in a way?
① 15N and 14N respectively, marked DNA.
② Because 15N DNA density than 14N DNA of density, density gradient
centrifugation in cesium chloride, the two different densities of the DNA located in a
different zone.
③ 15N heavy-density zone, 14N light-density zone, 15N and 14N-DNA medium
density zone.
④ degeneration before the hybrid molecule with a medium density, modified after the
zone is divided into two, namely, heavy density band (15N DNA) and low-density
zone (14N DNA). Only test the theory of semi-conservative replication to get a
satisfactory explanation.
2. Description of protein trans-membrane transport mechanism?
① In the process of protein synthesis in the N-terminal 15 to 36 amino acid residues
of the peptide --- signal peptide, that he could guide the protein peptide chain to reach
through the endoplasmic reticulum.
② then in the endoplasmic reticulum signal peptidase removed, protein N terminal
signal peptide does not.
③ In the cytosol there is a signal recognition particle (SRP), containing 300
nucleotides of the 7S small molecule RNA (small cytoplasm scRNA) and six kinds of
protein ribonucleoprotein, appears in the signal peptide, can identify and combine
signal peptide and the ribosome, so that translation pause, and with the membrane of
the SRP receptor protein (docking protein) binding, transmembrane peptide chain.
3. Respectively, say 5 or more RNA function?
tRNA amino acid transporter rRNA ribosomal component into a sub-mRNA protein
synthesis in a sub-template hnRNA mature mRNA precursor of a sub- snRNA
involved in splicing a sub-hnRNA
4. Examples of tissue-specific cDNA differential screening method?
① Preparation of two kinds of cell populations, gene expression, in which a cell or
high expression in the other cells did not express or low expression.
② then compared to find the target gene by hybridization.
③For example: in tumor occurrence and development process, the tumor cells and
normal cells showed different levels of the mRNA, therefore, can be screened by
differential hybridization with the tumor-related genes. Induction method can also be
used to screen out the genes induced.