Deck 8: Microbial Genetics and Genetic Engineering

Question 1

DNA polymerase III

A)is needed for adding nucleotides during mRNA synthesis.
B)synthesizes new DNA only in the 5' to 3' direction.
C)cannot add nucleotides to the lagging strand.
D)synthesizes an RNA primer.
E)All of the choices are correct.

Answer 1

B

Question 2

The antiparallel arrangement within DNA molecules refers to

A)each base bonding at the 1' position of the sugar.
B)a purine always bonding to a pyrimidine.
C)one helix strand that runs from the 5' to 3' direction and the other strand runs from the 3' to 5' direction.
D)an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.
E)None of the choices is correct.

Answer 2

C

Question 3

Okazaki fragments are attached to the growing end of the lagging strand by

A)DNA ligases.
B)DNA polymerases.
C)DNA helicases.
D)DNA gyrases
E)primases.

Answer 3

A

Question 4

During replication,each parent DNA strand serves as a _____ for synthesis of new DNA strands.

A)copy point
B)template
C)comparison molecule
D)scaffold
E)reservoir

Question 5

The expression of genetic traits is the

A)genome.
B)genotype.
C)proteome.
D)phenotype.
E)proteotype.

Question 6

The _____ is all of the genetic material of a cell.

A)chromosome
B)plasmid
C)prophage
D)genome
E)proteome

Question 7

The duplication of a cell's DNA is called

A)mitosis.
B)replication.
C)transcription.
D)translation.
E)mutation.

Question 8

Which of the following is not true of an organism's genotype?

A)is inherited
B)are structural genes coding for proteins
C)are genes coding for RNA
D)are regulatory genes controlling gene expression
E)are the expressed traits governed by the genes

Question 9

The site where the old DNA strands separate and new DNA strands will be synthesized is called the

A)primer.
B)Okazaki fragment.
C)template.
D)rolling circle.
E)replication fork.

Question 10

Each _____ is a specific segment of the DNA with the code for production of one functional product.

A)intron
B)exon
C)gene
D)operator
E)triplet

Question 11

Among the microorganisms,various genomes can include

A)chromosomes.
B)plasmids.
C)mitochondrial DNA.
D)chloroplast DNA.
E)All of the choices are correct.

Question 12

Which is incorrect about purines?

A)only found in DNA,not in RNA
B)are nitrogenous bases
C)always paired with a specific pyrimidine
D)include adenine and guanine
E)found within nucleotides

Question 13

Structural genes code for

A)ribosomal RNA molecules.
B)transfer RNA molecules.
C)cellular proteins.
D)gene expression elements.
E)All of the choices are correct.

Question 14

All of the following pertain to nitrogenous bases except

A)form pairs by hydrogen bonding.
B)guanine pairs with uracil.
C)adenine pairs with thymine.
D)cytosine and thymine are pyrimidines.
E)they are only present in the form of purines.

Question 15

Eukaryotic chromosomes differ from bacterial chromosomes because only eukaryotes have

A)histone proteins.
B)chromosomes in a nucleus.
C)several to many chromosomes.
D)elongated,not circular,chromosomes.
E)All of the choices are correct.

Question 16

Base pairs in DNA are held together by _____ bonds.

A)peptide
B)nonpolar covalent
C)polar covalent
D)hydrogen
E)sulfhydryl

Question 17

The enzymes that can proofread replicating DNA,detect incorrect bases,excise them,and correctly replace them are

A)DNA ligases.
B)DNA polymerases.
C)DNA helicases.
D)DNA gyrases.
E)primases.

Question 18

The DNA of microorganisms is made up of subunits called

A)histones.
B)amino acids.
C)nucleotides.
D)mRNA.
E)polymerases.

Question 19

Each nucleotide is composed of

A)one phosphate,one nitrogenous base,and one sugar.
B)one phosphate,one nitrogenous base,and two sugars.
C)two phosphates,one nitrogenous base,and one sugar.
D)two phosphates,one nitrogenous base,and two sugars.
E)one phosphate,two nitrogenous bases,and one sugar.

Question 20

Semiconservative replication refers to

A)each base bonding at the 1' position of the sugar.
B)a purine always bonding to a pyrimidine.
C)one helix strand that runs from the 5' to 3' direction and the other strand runs from the 3' to 5' direction.
D)an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.
E)None of the choices is correct.

Question 21

A sequence of bases on a gene that does not code for protein is called a(n)

A)promoter.
B)operator.
C)operon.
D)exon.
E)intron.

Question 22

Which molecule is synthesized as a copy of a gene on the DNA template strand?

A)ribosomal RNA
B)messenger RNA
C)transfer RNA
D)primer RNA
E)ribozymes

Question 23

Three consecutive bases in the DNA of a gene represent the code for one

A)protein.
B)nucleotide.
C)amino acid.
D)purine.
E)None of the choices is correct.

Question 24

DNA Polymerase I

A)removes primers.
B)adds bases to new DNA chain.
C)supercoils DNA.
D)unzips DNA.
E)synthesizes RNA primer.

Question 25

If the mRNA codon for alanine is GCA,then the correct anticodon would be:ev: 10_31_2012

A)GCA.
B)CGT.
C)ACG.
D)CGU.
E)UGC.

Question 26

RNA molecules differ from DNA molecules because only RNA

A)has ribose.
B)has uracil.
C)is typically one strand of nucleotides.
D)does not have thymine.
E)All of the choices are correct.

Question 27

All of the following pertain to transcription except

A)occurs on a ribosome in the cytoplasm.
B)occurs before translation.
C)requires RNA polymerase.
D)requires a template DNA strand.
E)proceeds in the 5' to 3' direction of the growing mRNA molecule.

Question 28

The nontranscribed region of DNA to which RNA polymerase binds to initiate transcription is called the

A)promoter.
B)operator.
C)operon.
D)exon.
E)intron.

Question 29

Which of the following is not associated with a bacterial ribosome?

A)is a 70S
B)has a peptide (P)site
C)has an exit site
D)small unit provides the enzymes for making peptide bonds
E)has an amino acid (A)site

Question 30

For DNA replication,a primer of ____ is needed at the origin of nucleotide addition.

A)polymerase III
B)polymerase I
C)helicase
D)RNA
E)DNA

Question 31

A permanent,inheritable change in the genetic information is called

A)translation.
B)transcription.
C)mutation.
D)alteration.
E)regeneration.

Question 32

Which of the following is incorrect about transfer RNA?

A)It has a bottom hairpin loop with an anticodon.
B)An anticodon is complementary to a codon.
C)It contains a binding site for an amino acid.
D)The initiator tRNA that binds to the P site has the anticodon UAC.
E)The initiator tRNA in bacteria carries tryptophan.

Question 33

Which of the following is incorrect about termination codons?

A)where the bond between the final tRNA and the finished polypeptide chain is broken
B)include AUG
C)include UAA,UAG,and UGA
D)do not have corresponding tRNA
E)can also be called nonsense codons

Question 34

The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called

A)ribosomal RNA.
B)messenger RNA.
C)transfer RNA.
D)primer RNA.
E)ribozymes.

Question 35

Replication of DNA begins at a(n)____ rich area.

A)guanine-cytosine.
B)uracil-adenine.
C)adenine-thymine.
D)adenine-cytosine.
E)guanine-adenine.

Question 36

The following pertain to ribosomes during protein synthesis except

A)they participate in both transcription and translation.
B)they participate only in translation.
C)they scans the mRNA for an AUG codon.
D)they are composed of ribosomal RNA and protein.
E)they shift to the right along the mRNA strand from one codon to the next.

Question 37

A three base sequence on mRNA is called a(n)

A)codon.
B)exon.
C)anticodon.
D)intron.

Question 38

Helicase

A)unzips DNA.
B)supercoils DNA.
C)unwinds RNA.
D)winds RNA.
E)None of the choices is correct.

Question 39

DNA Polymerase III

A)synthesizes primer.
B)removes primer.
C)joins Okazaki fragments.
D)unzips the DNA helix.
E)adds new bases and proofreads new DNA.

Question 40

Split genes

A)are common in bacteria and eukaryotes.
B)only have exons initially transcribed to mRNA.
C)have introns located only at the beginning and end of a coding region.
D)use spliceosomes to excise introns and then join exons.
E)All of the choices are correct.

Question 41

Which of the following is not true of conjugation?

A)It involves direct contact between cells.
B)It transfers genes for drug resistance.
C)It transfers genes for resistance to heavy metals.
D)It transfers genes for a polysaccharide capsule.
E)The donor retains a copy of the transferred genes.

Question 42

The development of virulent,toxin-producing bacterial strains due to the presence of a temperate phage can occur in

A)bacterial conjugation.
B)transformation.
C)generalized transduction.
D)specialized transduction.
E)All of the choices are correct.

Question 43

A mutation that changes a normal codon to a stop codon is called a

A)point mutation.
B)silent mutation.
C)back mutation.
D)missense mutation.
E)nonsense mutation.

Question 44

If the wild-type DNA sequence reads THE CAT ATE THE BIG RAT,what type of mutation would change the sequence to THE CAT ATA ETH EBI GRA T?

A)missense
B)nonsense
C)insertion
D)deletion
E)silent

Question 45

Which of the following is not a type of bacterial DNA recombination?

A)transformation
B)conjugation
C)mitosis
D)transduction
E)meiosis

Question 46

If the wild-type DNA sequence reads THE CAT ATE THE BIG RAT,what type of mutation would change the sequence to THE CAT ATE (stop)?

A)missense
B)nonsense
C)insertion
D)deletion
E)silent

Question 47

The process in which mutations are removed and the correct bases added is called

A)transduction.
B)excision repair.
C)frame shift.
D)back-mutation.
E)transformation.

Question 48

Which cell can transfer chromosomal and plasmid genes to a recipient cell by conjugation?

A)F⁺ cell
B)F^- cell
C)Hfr cell
D)R cell
E)B cell

Question 49

Which is incorrect about inducible operons?

A)have genes turned off by a buildup of end product
B)are often for catabolic pathways
C)are normally turned off
D)are turned on by the substrate of the enzyme
E)include the lac operon

Question 50

The most serious type of mutation is a

A)point mutation.
B)silent mutation.
C)frame shift mutation.
D)back mutation.
E)All the choices are equally serious.

Question 51

What type of mutation alters the base,but not the amino acid being coded for?

A)silent
B)back
C)point
D)nonsense
E)missense

Question 52

Full induction of the lactose operon requires

A)lactose present.
B)lactose and glucose present.
C)lactose present without glucose.
D)lactose and arabinose present.
E)All of the choices induce the lactose operon.

Question 53

A frame shift is caused by ______ mutations.

A)missense and insertion
B)missense and nonsense
C)nonsense and deletion
D)deletion and insertion
E)insertion and nonsense

Question 54

The transfer of DNA fragments from a dead cell to a live,competent recipient cell that results in a changed recipient cell is

A)transduction.
B)conjugation.
C)transformation.
D)transmission.
E)mitosis.

Question 55

The lactose repressor

A)is transcribed with the structural lac genes.
B)is activated by binding lactose.
C)is inactivated by binding lactose.
D)requires lactose for its transcription.
E)None of the choices is correct.

Question 56

If the wild-type DNA sequence reads THE CAT ATE THE BIG RAT,what type of mutation would change the sequence to THE CAT ATE THE BAG RAT?

A)missense
B)nonsense
C)insertion
D)deletion
E)silent

Question 57

Synthesis of an inducible enzyme requires

A)repressor alone bound to operator.
B)substrate bound to repressor.
C)substrate bound to promoter.
D)corepressor and repressor binding to operator.
E)None of the choices is correct.

Question 58

Gene regulation can involve a protein repressor that blocks _____ from initiating transcription.

A)DNA polymerase I
B)DNA polymerase III
C)RNA polymerase
D)mRNA
E)rRNA

Question 59

The gene that codes for a protein capable of repressing an operon is called the

A)operator.
B)structural locus.
C)regulator.
D)promoter.
E)None of the choices is correct.

Question 60

Bacterial conjugation involves

A)bacteriophage carrying donor DNA to the recipient cell.
B)a donor cell with a plasmid that synthesizes a pilus.
C)naked DNA fragments from a lysed donor cell taken up by a recipient cell.
D)new progeny cells with genes from two parent bacterial cells.
E)None of the choices is correct.

Question 61

All mutations are detrimental to the cell.

Question 62

DNA photolyase,in the presence of visible light,can repair DNA damage due to ultraviolet radiation.

Question 63

A technique that separates a readable pattern of DNA fragments is

A)genetic engineering.
B)biotechnology.
C)recombinant DNA.
D)gel electrophoresis.
E)gene probes.

Question 64

In bacteria,initiator tRNA carries formyl methionine.

Question 65

A bacteriophage transfers DNA of the previous host to the current host.This is an example of

A)conjugation.
B)generalized transduction.
C)specialized transduction.
D)a reaction of an Hfr cell.
E)None of the choices is correct.

Question 66

Excised introns form structures called lariats.

Question 67

Sequences of DNA that are identical when read from the 5' to 3' direction on one strand and the 3' to 5' direction on the other strand are

A)palindromes.
B)reverse transcriptase.
C)restriction endonucleases.
D)ligases.
E)DNA polymerases.

Question 68

Transcription occurs in the nucleus or at the nucleoid.

Question 69

Repressible operons are normally turned on in the cell.

Question 70

Lactose is a corepressor in the lac operon.

Question 71

DNA strands can be clipped crosswise at selected positions by using enzymes called

A)palindromes.
B)reverse transcriptase.
C)restriction endonucleases.
D)ligases.
E)DNA polymerases.

Question 72

The various techniques by which scientists manipulate DNA in the lab are called

A)genetic engineering.
B)biotechnology.
C)recombinant DNA.
D)gel electrophoresis.
E)gene probes.

Question 73

The jumping of a gene from one location to another is done by

A)conjugation.
B)transposons.
C)transformation.
D)transduction.
E)transmission.

Question 74

EcoRI and HindIII are

A)palindromes.
B)reverse transcriptase.
C)restriction endonucleases.
D)ligases.
E)DNA polymerases.

Question 75

The smallest unit of heredity is a chromosome.

Question 76

Analysis of DNA fragments in gel electrophoresis involves

A)larger fragments that move slowly and remain closer to the wells.
B)DNA that has an overall negative charge and moves to the positive pole.
C)DNA fragments that are stained to see them.
D)an electric current through the gel that causes DNA fragments to migrate.
E)All of the choices are correct.

Question 77

Which of the following is not true of transposons?

A)can change pigmentation
B)can replace damaged DNA
C)can transfer drug resistance
D)can change the genome
E)are always part of plasmids

Question 78

Geneticists can make complimentary DNA from messenger,transfer,and ribosomal RNA by using

A)palindromes.
B)reverse transcriptase.
C)restriction endonucleases.
D)ligases.
E)DNA polymerases.

Question 79

Induced mutations result from errors in DNA replication.

Question 80

DNA replication proceeds in one direction around the bacterial chromosome.