Question 1

Imagine you are a student trying to decode the genetic code. An artificial mRNA molecule consisting of poly-CA (5ʹ... CACACACACACACAC..3ʹ) yields a polypeptide consisting solely of histidines and threonine, and another artificial mRNA consisting of poly-CAA (5ʹ...CAACAACAACAACAA...3ʹ) yields three different polypeptides: polythreonine, polyglutamine, and polyasparagine. On the basis of this information, which codons can you assign to which amino acids?

Accepted Answer

The answer of Imagine you are a student trying to...

Question 2

RNA is copied from DNA through a process called _______.

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The answer of RNA is copied from DNA through a...

Question 3

What technique would you use to determine if the level of a specific mRNA had been increased in response to an inducer?

Accepted Answer

A)  Northern blotting 
B)  Southern blotting 
C)  Western blotting 
D)  Immunoprecipitation

Question 4

cDNA made from genomic DNA is used to create cDNA libraries.

Accepted Answer

A) True 
 B)False

Question 5

Why are dideoxynucleotides used in DNA sequencing?

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The answer of Why are dideoxynucleotides used in DNA sequencing?...

Question 6

The polymerase chain reaction is used to amplify specific fragments of DNA in vitro.

Accepted Answer

A) True 
 B)False

Question 7

Nucleic acid hybridization is the

Accepted Answer

A)  mating of two genetically different organisms. 
B)  formation of hybrid nuclei when two cells are fused. 
C)  formation of a double-stranded molecule from the interaction of two complementary-sequence single-stranded molecules. 
D)  recombining of DNA molecules from two different organisms.

Question 8

The enzyme that synthesizes DNA using RNA templates is called

Accepted Answer

A)  DNA polymerase. 
B)  RNA polymerase. 
C)  ribozymes. 
D)  reverse transcriptase.

Question 9

A restriction enzyme with a four-base recognition site would cleave DNA with a statistical frequency of once every

Accepted Answer

A)  4 base pairs. 
B)  256 base pairs. 
C)  4,096 base pairs. 
D)  65.5 kilobases.

Question 10

Addition or deletion of one or two nucleotides in the coding part of a gene produces a nonfunctional protein, whereas addition or deletion of three nucleotides often results in a protein with nearly normal function. Explain.

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The answer of Addition or deletion of one or two...

Question 11

When thymidine and adenosine interact within a DNA molecule, they form

Accepted Answer

A)  two hydrogen bonds. 
B)  three hydrogen bonds. 
C)  nucleotide triphosphates. 
D)  two phosphodiester bonds.

Question 12

Eggs and sperm are

Accepted Answer

A)  haploid. 
B)  diploid. 
C)  euploid. 
D)  tetraploid.

Question 13

In Meselson and Stahl's experiment, cells were grown in media containing 15N in place of 14N, and then the cells' DNA was separated by equilibrium centrifugation. This experiment demonstrated that DNA

Accepted Answer

A)  replication requires DNA polymerase. 
B)  replication is conservative. 
C)  replication is semiconservative. 
D)  forms double helices by means of hydrogen bonding between base pairs.

Question 14

If a plasmid does not contain an origin of replication, what would happen if you were to transfect it into bacteria?

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The answer of If a plasmid does not contain an...

Question 15

In experiments using polymerase chain reactions (PCR), it is often more difficult to amplify through regions of DNA that are high in GC content versus those regions that are either lower in GC content or are AT-rich. Based on your knowledge of DNA structure, explain why.

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The answer of In experiments using polymerase chain reactions (PCR),...

Question 16

According to the "central dogma" of molecular biology, information flows from DNA to RNA to protein. In its original version, the dogma stated that information does not flow in the reverse direction. To what extent is this true?

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The answer of According to the "central dogma" of molecular...

Question 17

RNA molecules that serve as templates for protein synthesis are called _______ RNAs.

Accepted Answer

A)  messenger 
B)  transfer 
C)  ribosomal 
D)  small nuclear

Exam 4: Fundamentals of Molecular Biology