testbank chapter 11 and 12
there are ___ different amino acids coded for by the different codons
20
RNA is always synthesized from the ______ to the ________ terminus
3' to 5' / 5' to 3'
bacteriophage nucleic acids was labeled by carrying out an infection of E. coli cells growing in a. 14C-labeled CO2 b. 3H-labeled water c. 32P-labeled phosphate d. 35S-labeled sulfate e. 18O-labeled water
32P-labeled phosphate
a protein is always synthesizes from the _____ to the _____ direction
5' , 3'
the number of different codons possible is _____
64
arthur kornberg showed that DNA could replicate in the test tube if it contained intact DNA for a template, a mixture of the four precursors of the four nucleoside triphosphates, and _____________________
DNA polymerase
if the double-stranded DNA molecule contains 30% T, how much G does it contain? a. 20% b. 30% c. 40% d. 50% e. 60%
a. 20%
the mRNA is synthesized in the _____________ direction which corresponds to the ______________ of the protein a. 5' to 3' ; N-term to C-term b. 3' to 5' ; C-term to N-term c. 5' to 3' ; C-term to N-term d. 3' to 5' ; N-term to C-term e. examples of all these have been found
a. 5' to 3' ; N-term to C-term
the direction of synthesis for a new mRNA molecule is a. 5' to 3' from a 5' to 3' template strand b. 5' to 3' from a 3' to 5' template strand c. 3' to 5' from a 5' to 3' template strand d. 3' to 5' from a 3' to 5' template strand e. 5' to 5' from a 3' to 3' template strand
a. 5' to 3' from a 5' to 3' template strand
the rules formulated by Erwin Chargaff state that a. A=T and G=C in any molecule of DNA b. A=C and G=T in any molecule of DNA c. A=G and C=T in any molecule of DNA d. A=U and G=C in any molecule of RNA e. DNA and RNA are made up of the same four nitrogenous bases
a. A=T and G=C in any molecule of DNA
which of the following molecules functions to transfer information from one generation to the next? a. DNA b. mRNA c. tRNA d. proteins e. lipids
a. DNA
which of the following molecules functions to transfer information from one generation to the next? a. DNA b. mRNA c. tRNA d. proteins e. lipids
a. DNA
How can DNA, made up of only 4 different bases, encode the information necessary to specify the workings of an entire organism? a. DNA molecules are extremely long. b. DNA molecules are found in the nucleus c. DNA is transcribed into RNA and then into proteins with specific functions. d. DNA is eventually translated into proteins, which are made up of 20 different amino acids. e. None of the above
a. DNA molecules are extremely long
every three bases (AUG) codes for one a. amino acid b. nucleotide c. carbohydrate d. lipid e. protein
a. amino acid
tRNA is involved in a. carrying amino acids b. carrying glucose c. carrying a ribosomes d. carrying lipids e. two are correct
a. carrying amino acids
semiconservation replication of DNA involves a. each of the original strands acting as a template for a new strand b. only one of the original strands acting as a template for a new strand. c. the complete separation of the original strands, the synthesis of new strands and the reassembly of double-stranded molecules d. the use of the original double-stranded molecule as a template, without unwinding. e. none of the choices
a. each of the original strands acting as a template for a new strand
which feature of the Watson and Crick model of DNA structure explains its ability to function in replication and gene expression? a. each strand contains all the information present in the double helix b. structural and functional similarities of DNA and RNA c. the double helix is right-handed and not left-handed d. DNA replication does not require enzyme catalysts e. exposure of the bases in the major groove of the double helix
a. each strand contains all the information present in the double helix
the structure of the DNA molecule was first discovered in a. in the 1850's b. in the 1950's c. in the 1990's d. it is still being discovered e. it is too small to discover
a. in the 1850's
transcription occurs a. in the nucleus b. in the cytosol c. in the ER d. all of these expect outside of the cell e. outside the cell
a. in the nucleus
in the Meselson-Stahl experiment, the conservation model of DNA replication is ruled out by which of the following observation? a. no completely heavy DNA is observed after the first round of replication b. no completely light DNA ever appears, even after several replication c. the product the accumulate after two rounds of replication is completely "heavy." d. completely "heavy" DNA is observed throughout the experiment e. three different DNA densities are observed after a single round of replication
a. no completely heavy DNA is observed after the first round of replication
the correct order of events for synthesis of the lagging strand is a. primase adds RNA primer, DNA polymerase III creates a stretch, DNA polymerase I removes the primer, and ligase seals the gaps b. primase adds primer, DNA polymerase I removes the primer, DNA polymerase I, polymerase III extends the segment, and ligase seals the gap c. ligase adds bases to the primase, the primase generates the polymerase I, polymerase III adds to the stretch, helicase winds to DNA. d. Helicase unwinds the DNA, primase creates a primer, DNA polymerase I elongates the stretch, DNA polymerase III removes the primer, and ligase seals the gaps in the DNA. e. none of the choices
a. primase adds RNA primer, DNA polymerase III creates a stretch, DNA polymerase I removes the primer, and ligase seals the gaps
the structure of DNA is characterized by a a. right-or left-handed double helix and antiparallel strands b. right-handed double helix and antiparallel strands c. right-handed single helix d. right-handed single helix and parallel strands e. all choices are true
a. right-or left handed double helix and antiparallel strands
After irradiating Neurospora, Beadle and Tatum collected mutants that require arginine to grow these mutants a. will not grow on minimal media but will grow on minimal media with arginine b. will not grow on minimal media and will not grow on minimal media with arginine c. will grow on minimal media and will grow on minimal media with arginine d. none of the above
a. will not grow on minimal media but will grow on minimal media with arginine
which type of radiation is LEAST likely to cause mutations in cells deep inside of the body? a. x-rays b. UV light c. gamma rays d. alpha radiation e. radon
a. x rays
the nitrogenous bases classified as purines are ___________ and ______________
adenine, guanine
in eukaryotes, Okazaki fragments are about __________ long. a. 50 base pairs b. 150 base pairs c. 1,500 base pairs d. 150,000 base pairs e. 15,000,000 base pairs
b. 150 base pairs
in Griffith's experiments, what happened when heat-killed S strain pneumococci were injected into a mouse along with live R strain pneumococci? a. DNA from the live R was taken up by the heat-killed S, converting it to R and killing the mouse b. DNA from the heat-killed S was taken up by the live R, converting it to S and killing the mouse c. proteins released from the heat-killed S was translated into proteins that killed the mouse d. RNA from heat-killed S was translated into proteins that killed the mouse e. none of the above
b. DNA from the heat-killed S was taken up by the live R, converting it to S and killing the mouse
the Hershey and Chase experiment convinced most scientists that a. bacteria can be transformed b. DNA is indeed the carrier of hereditary information] c. DNA replication is semiconservative d. the transforming principle requires host factors e. all of the choices
b. DNA is indeed the carrier of hereditary information
a transcription start signal is called a. an initiation codon b. a promoter c. a origin d. an operator e. a nonsense codon
b. a promoter
termination of transcription involves a. a stop codon b. a terminator sequence c. a termiproteator d. a hairline slip e. series of A'S
b. a terminator sequence
in order to show that DNA is the "transforming principle," Avery, MacLeod, and McCarty showed that DNA could transform avirulent strains of pneumococcus. This hypothesis was strengthened by their demonstration that a. enzymes that destroyed proteins also destroyed transforming activity b. enzymes that destroyed nucleic acids also destroyed transforming activity c. enzymes that destroyed complex carbohydrates also destroyed transforming activity d. the transformation activity was destroyed by boiling e. other strains of bacteria could also be successfully transformed
b. enzymes that destroyed nucleic acids also destroyed transforming activity
the enzyme DNA ligase is required continuously during DNA replication because a. fragments of the leading strand must be joined together b. fragments of the lagging strand must be joined together c. the parental strands must be joined back together d. 3'-deoxynucleoside triphosphates must be converted to 5' -deoxynucleotide trisphosphate e. the complex of proteins that work together at the replication fork must be kept from falling apart
b. fragments of the lagging strand must be joined together
mutations are a. heritable changes in the sequence of DNA bases that produce an observable b. heritable changes in the sequence of DNA bases c. mistake in the incorporation of amino acids into proteins d. heritable changes in the mRNA of an organism e. none of the choices
b. heritable changes in the sequence of DNA base
during replication, the new DNA strand is synthesized a. in the 3' to 5' direction b. in the 5' to 3' direction c. in both the 3' to 5', to 3' directions from the replication fork d. from one end to the other in the 3' to 5' or the 5' to 3' directions e. none of the choices
b. in the 5' to 3' direction
which of the following molecules functions to transfer information from the nucleus to the cytoplasm a. DNA b. mRNA c. tRNA d. proteins e. lipids
b. mRNA
the type of mutation that stops translation of proteins is a(n) a. missense mutation b. nonsense mutation c. frame-shift mutation d. aberration e. none of the above
b. nonsense mutation
the steps of the ladder are a. individuals nitrogenous base b. pairs of bases c. alternating bases and phosphate groups d. alternating sugars and bases e. alternating bases, sugars and phosphate
b. pairs of bases
ribosomes are a collection of a. small proteins that function in translocation b. proteins and small RNAs that function in translation c. proteins and tRNAs that function in transcription d. proteins and mRNAs that function in translation e. mRNAs and tRNAs that function in translation
b. proteins and small RNAs that function in translation
during DNA replication a. one parental strand must be degraded to allow the other strand to be copied b. the parental strands must separate so that both can be copied c. the parental strands come back together after the passage of the replication fork. d. origins of replication always give rise to single replication forks e. two replication forks diverge from each origin but one always lags behind the other
b. the parental strands must separate so that both can be copied
Why were fragments like those now called Okazaki fragments expected before they were discovered? a. DNA replicates in the 5' to 3' direction. b. The replication fork moves forward along a double-stranded DNA molecule. c. DNA replicates in the 3' to 5' direction on the lagging strand. d. RNA primase places short RNA primer sequences along the DNA molecule. e. DNA Polymerase I can connect short segments.
b. the replication fork moves forward along a double-stranded DNA molecule
The adapters that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called a. aminoacyl tRNA synthetases b. transfer RNAs c. ribosomal RNAs d. messenger RNAs e. ribosomes
b. transfer RNAs
the following RNA strand was produced 5'CGA GUG AAU CGU UAA 3' which of the following DNA strands could have been the template for this RNA? a. 3' CGA GUG AAU CGU UAA 5' b. 3' GCU CAC UUA GCA AUU 5' c. 3' GCT CAC TTA GCA ATT 5' d. 3' TTA ACG ATT CAC TCG 5' e. none of these are correct
c. 3' GCT CAC TTA GCA ATT 5'
the molecules that function to replicate DNA in the cell are a. DNA nucleotide triphosphates b. DNA polymerases c. nucleoside polyerases d. DNAses e. ribonucleases
c. DNA polymerases
the endoplasmic reticulum functions in protein synthesis a. as the site where mRNA attaches b. as the site where all ribosomes bind c. as the site of translation of membrane-bound and exported proteins d. to produce tRNAs e. to bring together mRNA and tRNA
c. as the site of translation of membrane-bound and exported proteins
the type of mutation that is an insertion or deletion of a single base is a(n) a. missense mutation b. nonsense mutation c. frame-shift mutation d. aberration e. none of the above
c. frame-shift mutation
the nitrogenous bases (and the two strands of the DNA double helix) are held together by a. weak van der waals forces b. covalent bonds c. hydrogen bonds d. ionic attractions e. magnetic attractions
c. hydrogen bonds
before the discovery of DNA, why was the hereditary material thought to be made of proteins and not nucleic acids? a. nucleic acids are made up of 20 different bases, while proteins are made up of only 5 amino acids b. protein subunits can combine to form larger proteins c. proteins seemed to be much more diverse chemically d. proteins can be enzymes e. none of the above
c. proteins seemed to be much more diverse chemically
experiments designed to identify the transforming principle were based on a. purifying each of the macromolecule types from a cell-free extract b. removing each of the macromolecules from a cell, then testing its type c. selectively destroying the different macromolecules in a cell-free extract d. no choice is correct
c. selectively destroying the different macromolecule in a cell-free extract
The antiparallel relationship of the two strands of DNA refers to the a. strands being the opposite of parallel, they are twisted b. strands providing alternative branching c. strands aligning such that one strand starts with a 3' carbon, the others with a 5' carbon d. view looking at one end of the molecule: one strand has an A wherever the other has a T, and one has a G wherever the other has a C. e. all of these choices
c. strands aligning such that one strand starts with a 3' carbon, the other with a 5' carbon
transcription is the process of a. synthesizing a DNA molecule from an RNA template b. assembling ribonucleotide triphosphates into an RNA molecule without a template c. synthesizing an RNA molecule using a DNA template d. synthesizing protein using information from a messenger RNA e. replicating a single-stranded DNA molecule
c. synthesizing an RNA molecule using a DNA template
which of the following molecules functions to transfer information from mRNA to protein? a. DNA b. mRNA c. tRNA d. protein e. lipids
c. tRNA
DNA replication in eukaryotes differs from replication in bacteria because a. synthesis of the new DNA strand is from 3' to 5' in eukaryotes and from 5' to 3' in bacteria b. synthesis of the new DNA strand is from 5' to 3' in eukaryotes and from 3' to 5' in bacteria c. there are many replication forks in each eukaryotic chromosome and only one in bacterial DNA d. synthesis of the new DNA strand in from 5' to 3' eukaryotes and is random in prokaryotes e. Okazaki fragments are produced in eukaryotic DNA replication but not in prokaryotic DNA replication
c. there are many replication forks in each eukaryotic chromosome and only one in bacterial DNA
Using Meselson and Stahl's experimental system for studying the mode of replication of DNA, the genetic information from a life form from Mars is analyzed. It is found that after the first round of replication, two distinct bands appear in the cesium chloride gradient. This is consistent with ________ replication.
conservation
the nitrogenous bases classified as pyrimidines are ___________ and __________
cytosine and thymine
RNA polymerase uses the ________________ DNA template to synthesize a _________________________ mRNA a. 5' to 3' ; 5' to 3' b. 3' to 5' ; 3' to 5' c. 5' to 3' ; 3' to 5' d. 3' to 5' ; 5' to 3' e. examples of all these have been found
d. 3' to 5' ; 5' to 3'
which of the following statements about the flow of genetic information is correct? a. proteins encode information that is used to produce other proteins of the same amino acid sequence b. proteins encode information that is translated into DNA, and DNA encodes information that is translated into proteins c. proteins encode information that can be translated into RNA and RNA encodes information that can be transcribed into RNA d. DNA encodes information that is translated into RNA, and RNA encodes information that is translated into proteins e. none of the above
d. DNA encodes information that is translated into RNA, and RNA encodes information that is translated into proteins
Why must RNA be incorporated into the DNA molecule initially during DNA replication? A) RNA primase adds bases that act as primers. B) RNA primase is able to use DNA as a template. C) RNA primase is incorporated into the holoenzyme complex. D) DNA polymerase I and III can only add on to an existing strand. E) All of the above
d. DNA polymerase I and III can only add on to an existing strand
what must RNA be incorporated into the DNA molecule initially during DNA replication? a. RNA primase adds bases that act as primers b. RNA primase is able to use DNA as a template c. RNA primase is incorporated into the holoenzyme complex d. DNA polymerase I and III can only add on to an existing strand
d. DNA polymerase I and III can only add on to an existing strand
the Hershey-Chase experiment determined that a. protein and DNA are the hereditary materials of viruses b. protein, not DNA is the hereditary material of viruses c. viruses do not contain hereditary material d. DNA, not protein, is the hereditary material of viruses e. the blender might be useful in the kitchen too
d. DNA, not protein, is the hereditary material of viruses
The study of Neurospora mutants that grew on various supplemented media led to a. determining the steps in biological pathways. b. the "one-gene, one-enzyme" theory. c. the idea that genes are "on" chromosomes. d. a and b e. a and c
d. a and b
a sequence of three ribonucleic acid base can function as a a. codon b. anticodon c. gene d. a and b e. a and c
d. a and b
the difference between mRNA and tRNA is that a. tRNA has more elaborate three-dimensional structure due to extensive base pairing b. tRNAS are usually very much smaller than mRNAS c. mRNA has a more elaborate three-dimensional structure due to extensive base pairing b. a and b e. none of the above
d. a and b
the base paired structure of DNA implies that it a. can replicate to form identical molecules b. can be used as a template to make RNA c. is the hereditary material d. all choices but one is correct
d. all choices but one is correct
genes code for a. enzymes b. polypeptides c. RNA d. all of the above e. none of the above
d. all of the above
double-stranded DNA looks a little like ladder that has been twisted into a helix, or spiral the side supports of the ladder are a. individual nitrogenous base b. alternating bases and sugar c. alternating bases and phosphate groups d. alternating sugars and phosphate e. alternating bases, sugar and phosphate
d. alternating sugar and phosphate
during infection of E. coli cells by bacteriophage T2 a. proteins are the only phage components that actually enter the infected cell. b. both proteins and nucleic acids enter the cell c. only protein from the infecting phage can also be detected in progeny phage d. only nucleic acids enter the cell e. more than one infecting phage particle is required to produce infection
d. only nucleic acids enter the cell
you have analyzed the DNA isolated from a newly discovered virus and found that its base composition is 32% A, 17% C, 32% G, and 19% T. what would be a reasonable explanation of the observation a. the virus must be extraterrestrial b. in some viruses, double-stranded DNA is made up of base pairs containing two purines or two pyrimidines c. some of the T was converted to C during the isolation procedure d. the genome of that phage is single-stranded, not double-stranded e. the genome of the phage must be circular, not linear
d. the genome of the phage is single-stranded, not double stranded
the number of codons that actually specify amino acids is a. 20 b. 23 c. 45 d. 60 e. 61
e. 61
Purines include a. cytosine, uracil, and thymine. b. adenine and cytosine. c. adenine and thymine. d. cytosine and thymine. e. adenine and guanine.
e. adenine and guanine
which of the following features summarizes the molecular architecture of DNA? a. the two strands run in opposite directions b. the molecule twists in the same direction as the threads of most screws c. the molecule is a double-stranded helix d. DNA has a uniform diameter e. all of the choices
e. all of the choices
translation depends on a. ribosomes b. tRNA's c. mRNA d. aminoacyl-tRNA synthetase e. all of these are required
e. all of these are required
the benefit mentioned for methylation of cytosine to the cells of some eukaryotic species was a. increase rates of DNA replication b. slowing of DNA replication c. improved separation of DNA strands d. improved proofreading e. improved mismatch repair
e. improved mismatch repair
translation occurs a. in the nucleus b. in the cytosol c. in the ER d. in all of these expect outside of the cell e. outside of the cell
e. outside of the cell
what are the three major properties of genes that are explained by the structure of DNA? a. they contain information, direct the synthesis of RNA and are contained in the cell nucleus b. they contain nitrogenous bases, direct the synthesis of RNA, and are contained in the cell nucleus c. they replicate exactly, are contained in the cell nucleus, and direct the synthesis of cellular proteins d. they encode the organism's phenotype, are passed on from one generation to the next, and contain nitrogenous bases e. they contain information, replicate exactly and change to produce a mutation
e. they contain information, replicate exactly and change to produce a mutation
information used by Watson and Crick to determine the structure of DNA included a. electron micrographs of individual DNA molecules b. light micrographs of bacteriophage particles c. light micrographs of individual bacteria chromosomes d. nuclear magnetic resonance analysis of DNA e. x-ray crystallography of double-stranded DNA
e. x-ray crystallography of double-stranded DNA
A ______________________ is a mutation that might cause protein sequence to be entirely different from certain point from what it was before
frameshift
a ______________________ is a mutation that changes the "reading frame"
frameshift
the enzyme that replicates the lagging strand is called _______________ in prokaryotes
helicase
since the DNA molecule runs on and on, without kinks or bulges, nucleotide pair after nucleotide pair, information must lie in the _________ sequence of the nitrogenous base
linear
the purines take up ___________ space in the center of a DNA molecules
more
a _____________ is a heritable change in a DNA molecule
mutation
the basic units of DNA and RNA molecules are the _____________
nucleotides
the fragments of RNA and DNA found on the lagging strand of DNA prior to RNA removal and ligation are called ________________________
okazaki fragments
the region of DNA where replication begins is an __________________________
origin of replication
the _________________________ function of the DNA polymerase reduces the number of mistake by the square of the frequency of the error rate
proof reading
the experiments of meselson and stahl established the ____________________________________________ of DNA
semi conservation replication
the strand of DNA that is actually used to transcribe RNA is the ____________ strand
template
a stop codon codes for ____________ (amino acid)
termination (UGA)
the material that changed R strain pneumococcus into the virulent S strain was originally referred to as the _________________ factor
transforming
when a piece of chromosome breaks off and joins to another it is called a
translocation
RNA differs from DNA in base composition because it contains __________ instead of thymine
uracil
the fact that some tRNA molecules do not have to pair exactly is called
wobble
