8 Micro – Genetics

Among the microorganisms, various genomes can include
A. chromosomes.
B. plasmids.
C. mitochondrial DNA.
D. chloroplast DNA.
E. All of the choices are correct.

E. All of the choices are correct.

Eukaryotic chromosomes differ from prokaryotic 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.

E. All of the choices are correct.

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

E. are the expressed traits governed by the genes

The _____ is all of the genetic material of a cell.
A. chromosome
B. plasmid
C. prophage
D. genome
E. proteome

D. genome

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

C. gene

The expression of genetic traits is the
A. genome.
B. genotype.
C. proteome.
D. phenotype.
E. proteotype.

D. phenotype.

The DNA of microorganisms is made up of subunits called
A. histones.
B. amino acids.
C. nucleotides.
D. mRNA.
E. polymerases.

C. nucleotides.

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

A. only found in DNA, not in RNA

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.

C. one helix strand that runs from the 5′ to 3′ direction and the other strand runs from the 3′ to 5′ direction.

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.

B. guanine pairs with uracil.

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.

A. one phosphate, one nitrogenous base, and one sugar.

Base pairs in DNA are held together by _____ bonds.
A. peptide
B. nonpolar covalent
C. polar covalent
D. hydrogen
E. sulfhydryl

D. hydrogen

The duplication of a cell’s DNA is called
A. mitosis.
B. replication.
C. transcription.
D. translation.
E. mutation.

B. replication.

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.

C. cellular proteins.

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

B. template

Semi-conservative 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.

D. an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.

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.

B. synthesizes new DNA only in the 5′ to 3′ direction.

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.

A. DNA ligases.

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.

B. DNA polymerases.

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.

E. replication fork.

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

A. unzips DNA.

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

A. removes primers.

DNA Polymerase III
A. synthesizes primer.
B. removes primer.
C. joins Okazaki fragments.
D. unzips the DNA helix.
E. proofreads new DNA.

E. proofreads new DNA.

A permanent, inheritable change in the genetic information is called
A. translation.
B. transcription.
C. mutation.
D. alteration.
E. regeneration.

C. mutation.

Replication of DNA begins at a/an
A. guanine-cytosine rich area.
B. uracil-adenine rich area.
C. adenine-thymine rich area.
D. adenine-cytosine rich area.
E. guanine-adenine rich area.

C. adenine-thymine rich area.

A primer of ____ is needed at the origin of nucleotide addition.
A. polymerase III
B. polymerase I
C. helicase
D. RNA
E. DNA

D. RNA

Groups of three consecutive bases along the DNA of a gene have the code for one
A. protein.
B. nucleotide.
C. amino acid.
D. purine.
E. None of the choices is correct.

C. amino acid.

The three base sequence on DNA is called a/an
A. codon.
B. exon.
C. anticodon.
D. intron.
E. triplet.

E. triplet.

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.

C. transfer RNA.

This 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

B. messenger RNA

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.

E. All of the choices are correct.

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.

A. occurs on a ribosome in the cytoplasm.

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.

A. promoter.

Which of the following is incorrect about transfer RNA?
A. has a bottom hairpin loop with an anticodon
B. an anticodon is complementary to a codon
C. contains a binding site for an amino acid
D. the initiator tRNA that binds to the P site has the anticodon UAC
E. initiator tRNA in bacteria carries tryptophan

E. initiator tRNA in bacteria carries tryptophan

If a codon for alanine is GCA, then the anticodon is
A. GCA.
B. CGT.
C. ACG.
D. CGU.
E. UGC.

D. CGU.

The following pertain to ribosomes during protein synthesis except
A. participate in both transcription and translation.
B. participate only in translation.
C. bind to the 5′ end of mRNA by their small subunit.
D. use their large subunit to supply enzymes for peptide bonding.
E. shift to the right along the mRNA strand from one codon to the next.

A. participate in both transcription and translation.

Which of the following is incorrect about termination codons?
A. are also called nonsense codons
B. where the bond between the final tRNA and the finished polypeptide chain is broken
C. include AUG
D. include UAA, UAG, and UGA
E. do not have corresponding tRNA

C. include AUG

Which of the following is not associated with a prokaryotic 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

D. small unit provides the enzymes for making peptide bonds

A sequence of bases on a gene that does not code for protein is called a/an
A. promoter.
B. operator.
C. operon.
D. exon.
E. intron.

E. intron.

Split genes
A. are common in prokaryotes 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.

D. use spliceosomes to excise introns and then join exons.

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

A. have genes turned off by a buildup of end product

The operon segment composed of the gene that codes for a protein capable of repressing the operon is called the
A. operator.
B. structural locus.
C. regulator.
D. promoter.
E. None of the choices is correct.

C. regulator.

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.

B. substrate bound to repressor.

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.

C. lactose present without glucose.

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.

C. is inactivated by binding lactose.

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

C. RNA polymerase

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.

E. nonsense mutation.

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.

C. frame shift mutation.

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

C. insertion

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

A. missense

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

B. nonsense

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

D. deletion and insertion

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

A. silent

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.

B. excision repair.

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.

B. a donor cell with a plasmid that synthesizes a pilus.

Which cell can transfer the most DNA?
A. F+ cell
B. F- cell
C. Hfr cell
D. R cell
E. B cell

C. Hfr cell

Which of the following is not a type of bacterial DNA recombination?
A. transformation
B. conjugation
C. mitosis
D. transduction
E. meiosis

C. mitosis

Which of the following is not true of conjugation?
A. involves direct contact between cells
B. transfers genes for drug resistance
C. transfers genes for resistance to heavy metals
D. transfers genes for a polysaccharide capsule
E. the donor retains a copy of the transferred genes

D. transfers genes for a polysaccharide capsule

Hfr transfer involves all of the following except
A. gene integration into the bacterial chromosome.
B. plasmid gene transfer.
C. F factor is part of the F+ donor chromosome.
D. high frequency transfer.
E. a pilus connection between F+ and F- cells.

B. plasmid gene transfer.

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.

C. transformation.

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.

D. specialized transduction.

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. reation of an Hfr cell.
E. None of the choices is correct.

B. generalized transduction.

The jumping of a gene from one location to another is done by
A. conjugation.
B. transposons.
C. transformation.
D. transduction.
E. transmission.

B. transposons.

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

E. are always part of plasmids

The smallest unit of heredity is a chromosome.

false

DNA replication proceeds in one direction around the bacterial chromosome.

false

Transcription occurs in the nucleus or at the nucleoid.

true

In bacteria, initiator tRNA carries formyl methionine.

true

Excised introns form structures called lariats.

true

Lactose is a corepressor in the lac operon.

false

Repressible operons are normally turned on in the cell.

true

Induced mutations result from errors in DNA replication.

false

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

true

All mutations are not beneficial to the cell.

false

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.

A. genetic engineering.

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.

D. gel electrophoresis.

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.

C. restriction endonucleases.

Geneticists can make complimentary DNA copies of messenger, transfer, and ribosomal RNA by using
A. palindromes.
B. reverse transcriptase.
C. restriction endonucleases.
D. ligases.
E. DNA polymerases.

B. reverse transcriptase.

EcoRI and HindIII are
A. palindromes
B. reverse transcriptase.
C. restriction endonucleases.
D. ligases.
E. DNA polymerases.

C. restriction endonucleases.

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.

A. palindromes.

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.

E. All of the choices are correct.

DNA is denatured at
A. 37 oC.
B. 42 oC.
C. 60 oC.
D. 90 oC.
E. 100 oC.

D. 90 oC.

DNA fragments can be separated in gel electrophoresis because
A. nitrogenous bases have a net positive charge.
B. nitrogenous bases have a net negative charge.
C. phosphate groups have a net positive charge.
D. phosphate groups have a net negative charge.
E. None of the choices is correct.

D. phosphate groups have a net negative charge.

Restriction endonucleases recognize and clip at DNA base sequences called
A. codons.
B. palindromes.
C. introns.
D. exons.
E. genes.

B. palindromes.

In recombinant DNA technique, what enzyme is needed to seal the sticky ends of genes into plasmids or chromosomes?
A. DNA polymerase I
B. DNA polymerase II
C. DNA helicase
D. DNA ligase
E. primase

D. DNA ligase

Labeled, known, short stretches of DNA used to detect a specific sequence of nucleotides in a mixture are known as
A. genetic engineering.
B. biotechnology.
C. recombinant DNA.
D. gel electrophoresis.
E. gene probes.

E. gene probes.

Two different nucleic acids can _____ by uniting at their complementary sites.
A. hybridize
B. covalently bond
C. form a peptide bond
D. ligate
E. None of the choices is correct.

A. hybridize

The size of DNA is often given in the number of _____ that it contains.
A. genes
B. codons
C. base pairs
D. proteins
E. triplets

C. base pairs

Amplification of DNA is accomplished by
A. polymerase chain reaction.
B. DNA sequencing.
C. gene probes.
D. southern blot.
E. western blot.

A. polymerase chain reaction.

DNA polymerases used in PCR
A. use an RNA template to make complementary DNA.
B. must remain active at very cold temperatures.
C. include Taq polymerase.
D. are labeled with fluorescent dyes.
E. All of the choices are correct.

C. include Taq polymerase.

Which PCR step causes the denaturation of double-stranded DNA?
A. add DNA polymerase and nucleotides at 72° C
B. cool DNA to between 50° C and 65° C
C. add primers
D. heat target DNA to 94° C
E. repeat the cycle of heating and cooling

D. heat target DNA to 94° C

Which PCR step synthesizes complimentary DNA strands?
A. add DNA polymerase and nucleotides at 72° C
B. cool DNA to between 50° C and 65° C
C. add primers
D. heat target DNA to 94° C
E. repeat the cycle of heating and cooling

A. add DNA polymerase and nucleotides at 72° C

The primers in PCR are
A. synthetic DNA oligonucleotides.
B. bacterial enzymes.
C. short RNA strands.
D. DNA polymerases.
E. reverse transcriptases.

A. synthetic DNA oligonucleotides.

If you start with 3 double-stranded DNA fragments, after 4 cycles of PCR you will have ____ fragments.
A. 12
B. 24
C. 27
D. 48
E. 81

D. 48

The deliberate removal of genetic material from one organism and combining it with the genetic material of another organism is a specific technique called
A. genetic engineering.
B. biotechnology.
C. recombinant DNA.
D. gel electrophoresis.
E. gene probes.

C. recombinant DNA.

Each of the following are features of a cloning host except
A. quick generation time.
B. minimal growth requirements.
C. mapped genome.
D. pathogenic.
E. transformable.

D. pathogenic.

Common vectors used to transfer a piece of DNA into a cloning host are
A. plasmids.
B. viruses.
C. bacteriophages.
D. artificial chromosomes.
E. All of the choices are correct.

E. All of the choices are correct.

Genomic _____ are collections of isolated genes maintained in a cloning host.
A. DNA
B. libraries
C. clones
D. digests
E. books

B. libraries

This is a promising treatment for stopping the expression of an unwanted gene:
A. cloning
B. gene therapy
C. antisense therapeutic
D. DNA fingerprinting
E. None of the choices is correct.

C. antisense therapeutic

Choose the antisense to the following mRNA sequence: AUGAUCCGCGAUU.
A. TACTAGGCGCTAA
B. AUGAUCCGCGAUU
C. UAGUAGCGGCUAA
D. UACUAGGCGCUAA
E. AU CAUCGCCCUAA

D. UACUAGGCGCUAA

Restriction endonucleases are obtained from various species of bacteria.

true

When DNA is heated, the two strands will separate.

true

Reverse transcriptase is used to make cDNA from an RNA template.

true

After 3 replication cycles in PCR, there will be a total of 3 double-stranded DNA molecules.

false

Viruses are often used as cloning hosts in recombinant DNA methods.

false

Vectors often contain a gene conferring drug resistance to their cloning host, in order to detect cells harboring the plasmid.

true

An example of gene therapy is the insertion of the gene for human growth hormone into E. coli cells.

false

It is now possible to very quickly map the genome of an organism or virus.

true

NCLEX Prep:

An 18-month-old male is admitted to the hospital with symptoms of a respiratory infection. The patient’s mother reports that since birth, the toddler has frequently had a cough and copious nasal secretions. His weight gain has been poor, despite adequate oral intake. The patient appears in moderate respiratory distress, so oxygen therapy and IV fluids are initiated. The physician orders tests for cystic fibrosis due to the patient’s history and clinical presentation. When the tests confirm the
diagnosis, as the RN, you provide education to the mother regarding this autosomal recessive disease.

Which of the following is the most appropriate term to describe the patient’s clinical manifestations of
cough, rhinorrhea, and poor weight gain due to this genetic disease?
A. genotype
B. phenotype
C. structural genes
D. regulatory genes

B. phenotype