Student Center | Instructor Center | Information Center | Home

	Biocourse.com
	NetTutor
	Web Links
	Information on Anthrax
	Microbiology in the News
	Careers in Microbiology
	Study Tips
	Correlation Guide to MiM III
	Glossary A-F
	Glossary G-L
	Glossary M-R
	Glossary S-Z
	Clinical Case Studies
	Interactive Time Line
	Lab Sequence Data


	Chapter Overview
	Chapter Objectives
	Study Outline
	Chapter Web Links
	Web Exercises
	Flash Cards
	Self-Quiz
	True or False

	Feedback Help Center

Microbiology, 5/e

Lansing M Prescott, Augustana College
Donald A Klein, Colorado State University
John P Harley, Eastern Kentucky University

Genes: Structure, Replication, and Mutation

Multiple Choice Quiz

Choose the best answer


1	The flow of genetic material in microbial cells usually proceeds from
		A)	Proteins through RNA to DNA
		B)	RNA through DNA to proteins
		C)	DNA through RNA to proteins


2	A new copy of a DNA molecule is precisely synthesized during a process called
		A)	translation
		B)	transcription
		C)	replication


3	The final step in gene expression is protein synthesis, or
		A)	translation
		B)	transcription
		C)	replication


4	The chromosome of almost all bacteria is in the shape of
		A)	an open circle
		B)	a closed circle
		C)	a linear chromosome


5	The enzyme that catalyzes the synthesis of DNA is called
		A)	helicase
		B)	DNA gyrase
		C)	DNA polymerase


6	The actual process of protein synthesis takes place on ribosomes that serve as workbenches, with _____________ acting as the blueprint or template.
		A)	DNA
		B)	mRNA
		C)	tRNA


7	DNA polymerase catalyzes the synthesis of DNA in the
		A)	3' to 5' direction
		B)	5' to 3' direction


8	The bases of one strand of DNA match-up with the bases of the second strand according to base pairing rules, therefore, the two strands are said to be
		A)	oppositely charged
		B)	complementary
		C)	identical


9	Eucaryotes are able to replicate their chromosomes in a relatively short period of time because
		A)	each chromosome contains multiple replicons
		B)	the eucaryotic replicative machinery is 1000 times faster than the procaryotic replicative machinery
		C)	eucarotic DNA is always single stranded


10	The enzymes that unwind short stretches of DNA helix immediately ahead of a replication fork are
		A)	single-stranded binding proteins
		B)	topoisomerases
		C)	helicases


11	The enzyme that repairs nicked DNA by forming a phosphodiester bond between adjacent nucleotides is
		A)	DNA gyrase
		B)	helicase
		C)	DNA ligase


12	The approximate rate of DNA replications in procaryotes is
		A)	10 bases per second
		B)	1,000 bases per second
		C)	100,000 bases per second


13	Another name for the three stop codons which aid in termination of translation is
		A)	nonsense codons
		B)	missense codons
		C)	pause codons


14	The enzyme that catalyzes the synthesis of RNA from a DNA template is
		A)	DNA gyrase
		B)	DNA ligase
		C)	RNA polymerase


15	Another name for the RNA polymerase recognition/binding site upstream of a gene is the
		A)	promoter
		B)	terminator
		C)	facilitator


16	The ____________ is nontranslated sequence that is located between the transcription start site and the translation start site
		A)	reading frame
		B)	leader sequence
		C)	trailer sequence


17	The Shine-Dalgarno sequence is
		A)	a short sequence that acts as a ribosomal binding site
		B)	another name for a stop codon
		C)	the reading frame of a gene


18	Most procaryotic proteins begin with this modified amino acid
		A)	N-formylleucine
		B)	N-formylmethionine
		C)	N-formylserine


19	Mutations may be characterized by
		A)	changes in genotype
		B)	changes in phenotype
		C)	changes in either genotype or phenotype


20	Mutations that arise without exposure to external agents are called
		A)	induced mutations
		B)	analogous mutations
		C)	spontaneous mutations


21	A mutagen is
		A)	a chemical or physical agent that induces mutations
		B)	an enzyme that repairs mutations
		C)	a molecule which stabilizes DNA thus prevents mutations from occurring


22	A mutation that affects only a single nucleotide is called
		A)	a regional mutation
		B)	a site mutation
		C)	a point mutation


23	A nonsense mutation results in
		A)	an abnormal elongation of a polypeptide
		B)	a premature termination of the synthesis of a polypeptide
		C)	a large deletion within the reading frame of a gene


24	The process by which thymine dimers are directly repaired with the help of visible light is called
		A)	photosynthesis
		B)	excision repair
		C)	photoreactivation


25	DNA repair mechanisms are able to distinguish newly synthesized DNA strands from older strands because
		A)	new strands do not contain cytosine bases
		B)	old strands are methylated while new strands are not
		C)	new strands are methylated while old strands are not


26	The ability of the anticodon of tRNA to interact with multiple codons of mRNA is called
		A)	promiscuity
		B)	wobble
		C)	stagger

2002 McGraw-Hill Higher Education
Any use is subject to the Terms of Use and Privacy Policy.
McGraw-Hill Higher Education is one of the many fine businesses of The McGraw-Hill Companies.