Multiple choice U6
DNA is copied during a process called a. replication. b. copying c. transcription. d. transformation.
a
During transcription, a. mRNA is produced. b. DNA is replicated. c. translation occurs. d. tRNA bring amino acids to mRNA.
a
If a DNA molecule were found to be composed of 40% thymine, what percentage of guanine would be expected? (Hint: you must account for each base.) A. 10% B. 20% C. 40% D. 80%
a
Transcription is the process by which genetic information encoded in DNA is transferred to a(n) a. RNA molecule. c. uracil molecule. b. DNA molecule. d. transposon.
a
Transfer RNA a. carries an amino acid to its correct codon. b. synthesizes amino acids as they are needed. c. produces codons to match the correct anticodons. d. converts DNA into mRNA.
a
Which of the following ensures that DNA replication produces two identical DNA molecules? a. An old strand serves as a template for a new stand. b. DNA polymerase unzips the double helix and checks for accuracy. c. DNA helicase adds new nucleotides to old nucleotides using the base pair rules. d. DNA replication is often not an accurate process.
a
mRNA: CUC—AAG—UGC—UUC Refer to the illustration above. The anticodons for the codons in the mRNA in the diagram are a. GAG—UUC—ACG—AAG. b. GAG—TTC—ACG—AAG. c. CUC—GAA—CGU—CUU. d. CUU—CGU—GAA—CUC.
a
During transcription, an RNA molecule is formed a. that is complementary to both strands of DNA. b. inside the nucleus. c. that is double-stranded. d. inside the ribosome.
b
The entire molecule (Nitrogen base, sugar, phosphate group) shown in the diagram is called a(n) a. amino acid. c. polysaccharide. b. nucleotide. d. pyrimidine.
b
The enzymes responsible for adding nucleotides to the exposed DNA template bases are a. replicases. c. helicases. b. DNA polymerases. d. None of the above
b
The part of the molecule for which deoxyribonucleic acid is named is the a. phosphate group. c. nitrogen base. b. sugar. d. None of the above
b
The two men who established the structure of DNA were: A. Frederick and Alvers B. Watson and Crick C. Berkely and Fry D. Darwin and Lamarck
b
Watson and Crick built models that demonstrated that a. DNA and RNA have the same structure. b. DNA is made of two strands that twist into a double helix. c. guanine forms hydrogen bonds with adenine. d. thymine forms hydrogen bonds with cytosine.
b
Which of the following is a nucleotide found in RNA? a. ribose + phosphate group + thymine b. ribose + phosphate group + uracil c. deoxyribose + phosphate group + cytosine d. deoxyribose + phosphate group + uracil
b
Which of the following is not true about DNA replication? a. It must occur before a cell can divide. b. Each new DNA molecule produced has two new DNA strands. c. The double strand unwinds and unzips while it is being duplicated. d. The process is catalyzed by helicase and polymerase.
b
mRNA: CUC—AAG—UGC—UUC Which of the following would represent the strand of DNA from which the mRNA strand in the diagram was made? a. GAG—UUC—ACG—AAG b. GAG—TTC—ACG—AAG c. CUC—AAG—UGC—UUC d. AGA—CCT—GTA—GGA
b
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 nucleotide triplet in mRNA that specifies a particular amino acid is called a(n) a. triplet. b. anticodon. c. codon. d. protein.
c
How many different codons are possible? A. 3 B. 20 C. 64 D. an infinite number
c
Suppose that you are given a protein containing the following sequence of amino acids: tyrosine, proline, aspartic acid, isoleucine, and cysteine. Use the portion of the genetic code given above to determine which of the possible answers contains a DNA sequence that codes for this amino acid sequence. a. AUG—GGU—CUA—UAU—ACG b. GCA—AAC—TCG—CGC—GTA c. ATG—GGT—CTA—TAT—ACG d. ATA—GGG—CTT—TAA—ACA
c
The enzymes that break hydrogen bonds and unwind DNA are: A. primers B. forks C. helicases D. polymerases
c
During DNA replication, a complementary strand of DNA is made for each original DNA strand. Thus, if a portion of the original strand is CCTAGCT, then the new strand will be a. TTGCATG. c. CCTAGCT. b. AAGTATC. d. GGATCGA.
d
Molecules of DNA are composed of long chains of a. amino acids. c. monosaccharides. b. fatty acids. d. nucleotides.
d
RNA differs from DNA in that RNA a. contains the nitrogen base uracil. b. is single-stranded. c. contains a different sugar molecule. d. All of the above
d
The amount of guanine in an organism always equals the amount of a. protein. c. adenine. b. thymine. d. cytosine.
d
What happens during the process of translation? a. Messenger RNA is made from DNA. b. Copies of DNA molecules are made. c. Transfer RNA is made from messenger RNA. d. The cell uses information from messenger RNA to produce proteins.
d
Which of the following is not part of a molecule of DNA? a. nitrogen base b. phosphate c. deoxyribose d. ribose
d
Which of the following is required for DNA replication to occur? A. DNA helicase B. DNA ligase C. DNA polymerase D. All of these
d
Which type of RNA functions as a copy of the genetic code? a. tRNA b. RNA polymerase c. rRNA d. mRNA
d
