Please answer all questions

1		A ________ codes for a specific sequence of amino acids in a protein.
			A)	gene
			B)	nucleotide
			C)	polyribosome
			D)	nucleic acid
2		Choose the characteristic that describes the DNA molecule.
			A)	four bases adenine, guanine, cytosine, and thymine
			B)	two strands of nucleotides twisted into a double helix
			C)	sugar phosphate backbone and complementary base-pairing in the interior
			D)	All of these are correct.
3		What event occurs first in the replication of DNA?
			A)	new nucleotides fit into place
			B)	new nucleotides are joined by DNA polymerase
			C)	enzymes unzip DNA molecule, breaking hydrogen bonds between bases
			D)	repair enzymes fix errors made during replication
4		RNA differs from DNA in a number of respects. What base is used in RNA that is not used in DNA?
			A)	thymine
			B)	uracil
			C)	adenine
			D)	guanine
5		Which of these is not a type of RNA used during protein synthesis in the cell?
			A)	ribosomal RNA
			B)	messenger RNA
			C)	transfer RNA
			D)	None of these are correct.
6		Messenger RNA carries genetic information from chromosomes to the ______.
			A)	ribosomes
			B)	endoplasmic reticulum
			C)	nucleolus
			D)	plasmids
7		Proteins are __________.
			A)	found in all parts of the body
			B)	used as enzymes to catalyze reactions
			C)	are composed of amino acids
			D)	All of these are correct.
8		DNA contains a triplet code in which every three ______ stand for one amino acid.
			A)	enzymes
			B)	sugars
			C)	phosphate groups
			D)	bases
9		_______ is the synthesis of an RNA molecule from a DNA template.
			A)	Transcription
			B)	Translation
			C)	Duplication
			D)	Cloning
10		Before messenger RNA (mRNA) leaves the nucleus, ___________.
			A)	mRNA is replicated
			B)	mRNA is processed and exons are removed
			C)	mRNA is processed and introns are removed
			D)	None of these is correct.
11		Transfer RNA anticodons pair complementarily to the ______ in mRNA.
			A)	sugar
			B)	codons
			C)	phosphate
			D)	ladders
12		Transfer RNA molecules come to the ribosomes in the order dictated by _______.
			A)	processed mRNA
			B)	rRNA
			C)	original DNA
13		Control of gene expression occurs at ____ levels.
			A)	two
			B)	three
			C)	four
			D)	five
14		Using recombinant DNA technology, a restriction enzyme _______.
			A)	removes a specific gene from human DNA
			B)	opens a bacterial plasmid
			C)	Both A and B are correct.
15		Gene ______ is achieved when a host cell takes up the recombined plasmid and the host and plasmid reproduce.
			A)	destruction
			B)	restructuring
			C)	cloning
			D)	flow
16		Free-living organisms with a foreign gene are called _______ organisms.
			A)	transposed
			B)	transmutated
			C)	transparent
			D)	transgenic
17		Genetically engineered bacteria have been formed that _______.
			A)	protect crop plants from common herbicides
			B)	protect crop plants from pests
			C)	Both A and B are correct.