Choose the best answer

1			Prokaryotes and eukaryotes use several methods to regulate gene expression, but the most common method is Need a Hint?
			A)	translational control.
			B)	transcriptional control.
			C)	posttranscriptional control.
			D)	control of mRNA passage from the nucleus.
2			The two protein subunits of the leucine zipper are held together Need a Hint?
			A)	in the shape of a Y.
			B)	by the interaction of leucine amino acids.
			C)	by hydrophobic interactions.
			D)	All of these are correct.
3			The helix-turn-helix motif contains two helical segments, and in order for the motif to bind DNA, the ______________ fits into the major groove of the DNA. Need a Hint?
			A)	homeodomain
			B)	recognition helix
			C)	zinc finger
			D)	leucine zipper
4			A(n) _______________ is a piece of DNA with a group of genes that are transcribed together as a unit. Need a Hint?
			A)	promoter
			B)	repressor
			C)	operator
			D)	operon
5			What effect would the addition of lactose have on a repressed lac operon? Need a Hint?
			A)	The operator site on the operon would move.
			B)	It would reinforce the repression of that gene.
			C)	The lac operon would be transcribed.
			D)	It would have no effect whatsoever.
6			A type of DNA sequence that is located far from a gene but can promote its expression is a(n) Need a Hint?
			A)	promoter.
			B)	activator.
			C)	enhancer.
			D)	TATA box.
7			Which of the following is not found in a eukaryotic transcription complex? Need a Hint?
			A)	activator
			B)	RNA
			C)	enhancer
			D)	TATA-binding protein
8			DNA methylation of genes Need a Hint?
			A)	inhibits transcription by blocking the base-pairing between methylated cytosine and guanine.
			B)	inhibits transcription by blocking the base-pairing between uracil and adenine.
			C)	prevents transcription by blocking the TATA sequence.
			D)	makes sure that genes that are turned off remain turned off.
9			Which of the following are not matched correctly? Need a Hint?
			A)	RNA splicing-occurs in the nucleus
			B)	snRNP-splicing out exons from the transcript
			C)	poly-A tail-increased transcript stability
			D)	All are matched correctly.
10			Which of the following is not a method of posttranscriptional control in eukaryotic cells? Need a Hint?
			A)	processing the transcript
			B)	selecting the mRNA molecules that are translated
			C)	digesting the DNA immediately after translation
			D)	selectively degrading the mRNA transcripts