Chooose the best answer

1			Which form of RNA acts as a blueprint for polypeptide biosynthesis by the ribosome?
			A)	mRNA
			B)	tRNA
			C)	rRNA
2			RNA is synthesized under the direction of DNA by this enzyme
			A)	DNA polymerase
			B)	DNA ligase
			C)	RNA polymerase
3			Which component of RNA polymerase facilitates the recognition of promoter sequences?
			A)	a subunit
			B)	b subunit
			C)	s subunit
4			The first hexameric sequence typically found in procaryotic promoters is located
			A)	at the transcription start site
			B)	approximately 35 bases upstream of the transcription start site
			C)	approximately 10 bases upstream of the transcription start site
5			What is the usual sequence of a Pribnow box?
			A)	TTGACA
			B)	TATAAT
			C)	UUUUUU
6			Following binding to a promoter, RNA polymerase next
			A)	unwinds a short segment of DNA
			B)	nicks one strand of DNA
			C)	begins to replicate DNA
7			Which of the following components is found in all procaryotic transcription terminators?
			A)	rho factor
			B)	a poly-U region
			C)	a hairpin structure
8			Posttranscriptional modification of RNA is more common in
			A)	procaryotes
			B)	eucaryotes
9			Which structure is found on eucaryotic mRNA but not procaryotic mRNA?
			A)	3' poly-A tail
			B)	5' cap
10			Which regions of interrupted genes code for RNA that will be present in the final RNA product?
			A)	introns
			B)	exons
			C)	promoter
11			What is a ribozyme?
			A)	a protein that synthesizes RNA
			B)	an RNA molecule that catalyzes a self-splicing reaction
			C)	a DNA molecule that acts as a template for RNA synthesis
12			What happens during amino acid activation?
			A)	a methyl group is attached to an amino acid
			B)	an amino acid is bound to mRNA
			C)	an amino acid is bound to tRNA
13			Which portion of a tRNA molecule is complementary to the mRNA triplet encoding a particular amino acid?
			A)	D arm
			B)	anticodon triplet
			C)	amino acid stem
14			Most procaryotic proteins begin with this modified amino acid
			A)	N-formylleucine
			B)	N-formylmethionine
			C)	N-formylserine
15			The most common initiator codon is
			A)	GUA
			B)	UAA
			C)	AUG
16			Which part of translation involves the addition of amino acids to an existing polypeptide chain?
			A)	initiation
			B)	elongation
			C)	termination
17			What molecule catalyzes the transpeptidation reaction?
			A)	peptidyl transferase
			B)	RNA polymerase
			C)	DNA ligase
18			Aminoacyl-tRNA binds to which site of the ribosome during elongation?
			A)	P site
			B)	A site
			C)	E site
19			Which of the following is NOT a nonsense codon?
			A)	AUG
			B)	UAA
			C)	UGA
20			What is the role of molecular chaperones?
			A)	to facilitate binding of ribosomes to mRNA
			B)	to degrade newly synthesized polypeptides that contain inaccurate sequences
			C)	to aid a newly synthesized polypeptide in folding to its proper shape
21			Many chaperones often are called ______________________ because of their expression under high temperatures.
			A)	heat-shock proteins
			B)	cold-shock proteins
			C)	thermostable protein
22			An enzyme whose amount is reduced by the presence of an end product are:
			A)	inducible enzymes
			B)	repressible enzymes
			C)	corepressors
23			A small molecule that causes the increase in levels of an inducible enzyme
			A)	repressor
			B)	corepressor
			C)	inducer
24			The operator is
			A)	another name for the terminator of a gene
			B)	a DNA site bound by repressor proteins
			C)	a protein that coordinates gene expression
25			The tryptophan operon in E.coli demonstrates a level of regulation called ______________ by the terminatation of transcription if tryptophan is abundant in cells.
			A)	activation
			B)	corepression
			C)	attenuation
26			Procaryotes have developed global regulatory systems
			A)	to aid in DNA replication
			B)	to regulate the regulation of many genes under varying environmental conditions
			C)	to determine the exact location of the cell on the globe
27			A collection of genes or operons that is controlled by a common regulatory proteins is called
			A)	a gene cluster
			B)	a genome
			C)	a regulon
28			A molecule of RNA that is complementary to a segment of another RNA molecule to which it will bind is called
			A)	antisense RNA
			B)	missense RNA
			C)	nonsense RNA
29			Which is not an essential part of a two-component phosphorelay system?
			A)	sensor kinase
			B)	response regulator
			C)	autoinducer