2Avery’s experiments showed that bacteria are transformed by RNA.DNA.proteins.carbohydrates.
3What did Griffith observe when he injected a mixture of heat-killed, disease-causing bacteria and live harmless bacteria into mice?The disease-causing bacteria changed into harmless bacteria.The mice developed pneumonia.The harmless bacteria died.The mice were unaffected.
4What would Hershey and Chase have concluded if both radioactive 32P and 35S were found in the bacteria in their experiment?The virus’s protein coat was not injected into the bacteria.The virus’s DNA was not injected into the bacteria.Genes are made of protein.Both the virus’s protein coat and its DNA were injected into the bacteria.
5The figure shows the structure of a(an) DNA molecule.amino acid.RNA molecule.protein.
6Which of the following is a nucleotide found in DNA? ribose + phosphate group + thymineribose + phosphate group + uracildeoxyribose + phosphate group + uracildeoxyribose + phosphate group + cytosine
7Because of base pairing in DNA, the percentage of adenine molecules in DNA is about equal to the percentage of guanine molecules.pyrimidines in DNA is about equal to the percentage of purines.purines in DNA is much greater than the percentage of pyrimidines.cytosine molecules in DNA is much greater than the percentage of guanine molecules.
8In eukaryotes, DNA is located in the nucleus. floats freely in the cytoplasm.is located in the ribosomes.is circular.
9During mitosis, the DNA molecules unwind. histones and DNA molecules separate.DNA molecules become more tightly coiled.nucleosomes become more tightly packed.
10Which of the following include all the others? DNA moleculeshistoneschromosomesnucleosomes
11DNA is copied during a process called replication.translation.transcription.transformation.
12DNA replication results in two DNA molecules, each with two new strands.one with two new strands and the other with two original strands.each with one new strand and one original strand.each with two original strands.
13During DNA replication, a DNA strand that has the bases CTAGGT produces a strand with the bases TCGAAC.GATCCA.AGCTTG.GAUCCA.
14RNA contains the sugarribose.deoxyribose.glucose.lactose.
16Which of the following are found in both DNA and RNA? ribose, phosphate groups, and adeninedeoxyribose, phosphate groups, and guaninephosphate groups, guanine, and cytosinephosphate groups, guanine, and thymine
17How many main types of RNA are there? 13hundredsthousands
18Which type(s) of RNA is(are) involved in protein synthesis? transfer RNA onlymessenger RNA onlyribosomal RNA and transfer RNA onlymessenger RNA, ribosomal RNA, and transfer RNA
19Which of the following are copied from DNA? mRNA onlymRNA, tRNA, and rRNAmRNA and tRNA onlyproteins
20What is produced during transcription? RNA moleculesDNA moleculesRNA polymeraseproteins
21During transcription, an RNA molecule is formed that is complementary to both strands of DNA.that is identical to part of a single strand of DNA.that is double-stranded.inside the nucleus.
22Which of the following statements is true? A promoter is part of an intron.A pre-mRNA molecule is longer than the gene from which the molecule was transcribed.Introns are sequences of DNA.Any mRNA molecules made from the same gene are always edited the same way.
23What does the figure show? anticodonsthe order in which amino acids are linkedthe code for splicing mRNAthe genetic code
24How many codons are needed to specify three amino acids? 36912
25Why is it possible for an amino acid to be specified by more than one kind of codon? Some codons have the same sequence of nucleotides.There are 64 different kinds of codons but only 20 amino acids.Some codons do not specify an amino acid.The codon AUG codes for the amino acid methionine and serves as the “start” codon for protein synthesis.
26What happens during the process of translation? Messenger RNA is made from DNA.The cell uses information from messenger RNA to produce proteins.Transfer RNA is made from messenger RNA.Copies of DNA molecules are made.
27Which of the following terms is LEAST closely related to the others? introntRNApolypeptideanticodon
28During translation, the type of amino acid that is added to the growing polypeptide depends on the codon on the mRNA only.anticodon on the mRNA only.anticodon on the tRNA to which the amino acid is attached only.codon on the mRNA and the anticodon on the tRNA to which the amino acid is attached.
29Genes contain instructions for assembling purines.nucleosomes.proteins.pyrimidines.
30Which type of RNA functions as a blueprint of the genetic code? rRNAtRNAmRNARNA polymerase
31Which of the following statements is false? Some genes code for enzymes.The instructions for making some proteins are not specified by genes.An organism’s inherited traits depend on proteins.An organism’s genes determine its inherited traits.
32A mutation that involves one or a few nucleotides is called a(an) chromosomal mutation.inversion.point mutation.translocation.
33Which of the following is NOT a gene mutation? inversioninsertiondeletionsubstitution
34Which of the following is NEVER a frameshift mutation? substitutioninsertiondeletionpoint mutation
35A promoter is a binding site for DNA polymerase. binding site for RNA polymerase.start signal for transcription.stop signal for transcription.
36Which of the following statements is true? A promoter determines whether a gene is expressed.An expressed gene is turned off.Proteins that bind to regulatory sites on DNA determine whether a gene is expressed.RNA polymerase regulates gene expression.
37If a specific kind of protein is not continually used by a cell, the gene for that protein is always transcribed.never expressed.turned on and off at different times.not regulated.
38In E. coli, the lac operon controls the breakdown of lactose.production of lactose.breakdown of glucose.production of glucose.
39A lac repressor turns off the lac genes by binding to the promoter.DNA polymerase.binding to the operator.binding to the lac genes.
40When E. coli is grown on glucose, lactose molecules bind to the lac repressor.the lac repressor binds to the operator of the lac operon.RNA polymerase binds to the promoter of the lac operon.the lac genes are transcribed.
41Which of the following is NOT generally part of a eukaryotic gene? operonTATA boxpromoter sequencesenhancer sequences
42Gene regulation in eukaryotes usually involves operons.is simpler than in prokaryotes.allows for cell specialization.includes the action of an operator region.
43Specialized cells regulate the expression of genes because they do not want the genes to become worn out.cannot control translation.do not carry the complete genetic code in their nuclei.do not need the proteins that are specified by certain genes.
44Hox genes determine an animal’s basic body plan.size.skin color.eye color.
45Which of the following statements is false? Mutations do not occur in hox genes.Hox genes that are found in different animals are very different from each other.Hox genes control the normal development of an animal.Hox genes occur in clusters.
46Hox genes are regulated by operons. are found in bacteria. are not found in humans.determine the location of a dog’s ears.
47The replication of a DNA molecule results in four copies of the same gene. TrueFalse
48DNA is tightly wrapped around nucleosomes. TrueFalse
49In eukaryotes, DNA replication proceeds in one direction along the DNA molecule. TrueFalse
50If a nucleic acid contains uracil, it is DNA. TrueFalse
51The nitrogenous bases in RNA are able to form hydrogen bonds with each other. TrueFalse
52During DNA replication, only one strand of DNA serves as a template. TrueFalse
57Without regulatory sites, the expression of a gene would not be controlled. TrueFalse
58In prokaryotes, an operon is a group of genes that are operated together. TrueFalse
59Gene regulation in eukaryotes is less complex than in prokaryotes. TrueFalse
60The TATA box in eukaryotes helps to ensure transcription. TrueFalse
61In fruit flies, the hox gene that controls the development of the wings is located before the hox gene that controls the development of the eye and before the hox gene that controls the development of the abdomen.TrueFalse