Chapter 12 Study Guide

Unlike DNA, RNA contains a. adenine. c. phosphate groups. b. uracil. d. thymine.

b. uracil.

How many codons are needed to specify three amino acids? a. 3 c. 9 b. 6 d. 12

a. 3

Figure 12-1 shows the structure of a(an) a. DNA molecule. c. RNA molecule. b. amino acid. d. protein.

a. DNA molecule.

What is produced during transcription? a. RNA molecules c. RNA polymerase b. DNA molecules d. proteins

a. RNA molecules

In E. coli, the lac operon controls the a. breakdown of lactose. c. breakdown of glucose. b. production of lactose. d. production of glucose.

a. breakdown of lactose.

Which of the following terms is LEAST closely related to the others? a. intron c. polypeptide b. tRNA d. anticodon

a. intron

Avery's experiments showed that bacteria are transformed by a. RNA. c. proteins. b. DNA. d. carbohydrates.

b. DNA.

How many main types of RNA are there? a. 1 c. hundreds b. 3 d. thousands

b. 3

A promoter is a a. binding site for DNA polymerase. c. start signal for transcription. b. binding site for RNA polymerase. d. stop signal for transcription.

b. binding site for RNA polymerase.

Which of the following include all the others? a. DNA molecules c. chromosomes b. histones d. nucleosomes

c. chromosomes

Which of the following is a nucleotide found in DNA? a. ribose + phosphate group + thymine b. ribose + phosphate group + uracil c. deoxyribose + phosphate group + uracil d. deoxyribose + phosphate group + cytosine

d. deoxyribose + phosphate group + cytosine

Hox genes a. are regulated by operons. c. are not found in humans. b. are found in bacteria. d. determine the location of a dog's ears.

d. determine the location of a dog's ears.

Hox genes determine an animal's a. basic body plan. c. skin color. b. size. d. eye color.

a. basic body plan.

Which of the following is NOT a gene mutation? a. inversion c. deletion b. insertion d. substitution

a. inversion

In eukaryotes, DNA a. is located in the nucleus. c. is located in the ribosomes. b. floats freely in the cytoplasm. d. is circular.

a. is located in the nucleus.

Which of the following is NOT generally part of a eukaryotic gene? a. operon c. promoter sequences b. TATA box d. enhancer sequences

a. operon

DNA is copied during a process called a. replication. c. transcription. b. translation. d. transformation.

a. replication.

RNA contains the sugar a. ribose. c. glucose. b. deoxyribose. d. lactose.

a. ribose.

Which of the following is NEVER a frameshift mutation? a. substitution c. deletion b. insertion d. point mutation

a. substitution

During DNA replication, a DNA strand that has the bases CTAGGT produces a strand with the bases a. TCGAAC. c. AGCTTG. b. GATCCA. d. GAUCCA.

b. GATCCA

Which of the following statements is false? a. Mutations do not occur in hox genes. b. Hox genes that are found in different animals are very different from each other. c. Hox genes control the normal development of an animal. d. Hox genes occur in clusters.

b. Hox genes that are found in different animals are very different from each other.

What happens during the process of translation? a. Messenger RNA is made from DNA. b. The cell uses information from messenger RNA to produce proteins. c. Transfer RNA is made from messenger RNA. d. Copies of DNA molecules are made.

b. The cell uses information from messenger RNA to produce proteins.

Which of the following statements is false? a. Some genes code for enzymes. b. The instructions for making some proteins are not specified by genes. c. An organism's inherited traits depend on proteins. d. An organism's genes determine its inherited traits.

b. The instructions for making some proteins are not specified by genes.

What did Griffith observe when he injected a mixture of heat-killed, disease-causing bacteria and live harmless bacteria into mice? a. The disease-causing bacteria changed into harmless bacteria. b. The mice developed pneumonia. c. The harmless bacteria died. d. The mice were unaffected.

b. The mice developed pneumonia.

Why is it possible for an amino acid to be specified by more than one kind of codon? a. Some codons have the same sequence of nucleotides. b. There are 64 different kinds of codons but only 20 amino acids. c. Some codons do not specify an amino acid. d. The codon AUG codes for the amino acid methionine and serves as the "start" codon for protein synthesis.

b. There are 64 different kinds of codons but only 20 amino acids.

Which of the following are copied from DNA? a. mRNA only c. mRNA and tRNA only b. mRNA, tRNA, and rRNA d. proteins

b. mRNA, tRNA, and rRNA

Because of base pairing in DNA, the percentage of a. adenine molecules in DNA is about equal to the percentage of guanine molecules. b. pyrimidines in DNA is about equal to the percentage of purines. c. purines in DNA is much greater than the percentage of pyrimidines. d. cytosine molecules in DNA is much greater than the percentage of guanine molecules.

b. pyrimidines in DNA is about equal to the percentage of purines.

When E. coli is grown on glucose, a. lactose molecules bind to the lac repressor. b. the lac repressor binds to the operator of the lac operon. c. RNA polymerase binds to the promoter of the lac operon. d. the lac genes are transcribed.

b. the lac repressor binds to the operator of the lac operon.

Which of the following statements is true? a. A promoter is part of an intron. b. A pre-mRNA molecule is longer than the gene from which the molecule was transcribed. c. Introns are sequences of DNA. d. Any mRNA molecules made from the same gene are always edited the same way.

c. Introns are sequences of DNA.

Which of the following statements is true? a. A promoter determines whether a gene is expressed. b. An expressed gene is turned off. c. Proteins that bind to regulatory sites on DNA determine whether a gene is expressed. d. RNA polymerase regulates gene expression.

c. Proteins that bind to regulatory sites on DNA determine whether a gene is expressed.

Gene regulation in eukaryotes a. usually involves operons. b. is simpler than in prokaryotes. c. allows for cell specialization. d. includes the action of an operator region.

c. allows for cell specialization.

A lac repressor turns off the lac genes by a. binding to the promoter. c. binding to the operator. b. DNA polymerase. d. binding to the lac genes.

c. binding to the operator.

DNA replication results in two DNA molecules, a. each with two new strands. b. one with two new strands and the other with two original strands. c. each with one new strand and one original strand. d. each with two original strands.

c. each with one new strand and one original strand.

Which type of RNA functions as a blueprint of the genetic code? a. rRNA c. mRNA b. tRNA d. RNA polymerase

c. mRNA

Which of the following are found in both DNA and RNA? a. ribose, phosphate groups, and adenine b. deoxyribose, phosphate groups, and guanine c. phosphate groups, guanine, and cytosine d. phosphate groups, guanine, and thymine

c. phosphate groups, guanine, and cytosine

A mutation that involves one or a few nucleotides is called a(an) a. chromosomal mutation. c. point mutation. b. inversion. d. translocation.

c. point mutation.

Genes contain instructions for assembling a. purines. c. proteins. b. nucleosomes. d. pyrimidines.

c. proteins.

If a specific kind of protein is not continually used by a cell, the gene for that protein is a. always transcribed. c. turned on and off at different times. b. never expressed. d. not regulated.

c. turned on and off at different times.

What would Hershey and Chase have concluded if both radioactive 32P and 35S were found in the bacteria in their experiment? a. The virus's protein coat was not injected into the bacteria. b. The virus's DNA was not injected into the bacteria. c. Genes are made of protein. d. Both the virus's protein coat and its DNA were injected into the bacteria.

d. Both the virus's protein coat and its DNA were injected into the bacteria.

During translation, the type of amino acid that is added to the growing polypeptide depends on the a. codon on the mRNA only. b. anticodon on the mRNA only. c. anticodon on the tRNA to which the amino acid is attached only. d. codon on the mRNA and the anticodon on the tRNA to which the amino acid is attached.

d. codon on the mRNA and the anticodon on the tRNA to which the amino acid is attached.

Specialized cells regulate the expression of genes because they a. do not want the genes to become worn out. b. cannot control translation. c. do not carry the complete genetic code in their nuclei. d. do not need the proteins that are specified by certain genes.

d. do not need the proteins that are specified by certain genes.

During transcription, an RNA molecule is formed a. that is complementary to both strands of DNA. b. that is identical to part of a single strand of DNA. c. that is double-stranded. d. inside the nucleus.

d. inside the nucleus.

Which type(s) of RNA is(are) involved in protein synthesis? a. transfer RNA only b. messenger RNA only c. ribosomal RNA and transfer RNA only d. messenger RNA, ribosomal RNA, and transfer RNA

d. messenger RNA, ribosomal RNA, and transfer RNA

During mitosis, the a. DNA molecules unwind. b. histones and DNA molecules separate. c. DNA molecules become more tightly coiled. d. nucleosomes become more tightly packed.

d. nucleosomes become more tightly packed.

What does Figure 12-2 show? a. anticodons b. the order in which amino acids are linked c. the code for splicing mRNA d. the genetic code

d. the genetic code