Chapter Questions
Beadle and Tatum (a) predicted that tRNA molecules would have anticodons (b) discovered the genetic disease alkaptonuria (c) showed that the genetic disease sickle cell anemia is caused by a change in a single amino acid in a hemoglobin polypeptide chain (d) worked out the genetic code (e) studied the relationship between genes and enzymes in Neurospora
What is the correct order of information flow in bacterial and eukaryotic cells? (a) DNA $\longrightarrow$ mRNA $\longrightarrow$ protein (b) pro$\operatorname{ten} \longrightarrow \mathrm{mRNA} \longrightarrow \mathrm{DNA}$ (c) DNA $\longrightarrow$ protein $\longrightarrow$ (e) $\mathrm{mRNA} \longrightarrow$ $\mathrm{mRNA}(\mathrm{d})$ protein $\longrightarrow \mathrm{DNA} \longrightarrow \mathrm{mRNA}$ protein $\longrightarrow$ DNA
During transcription, how many RNA nucleotide bases would usually be encoded by a sequence of 99 DNA nucleotide bases? (a) 297 (b) 99 (c) 33 (d) 11 (e) answer is impossible to determine with the information given
The genetic code is defined as a series of __________ in ____________ . (a) anticodons; tRNA (b) codons; DNA (c) anticodons; mRNA (d) codons; mRNA (e) codons and anticodons; rRNA
Transcription is the process by which ___________ is/are synthesized. (a) mRNA only (b) mRNA and tRNA (c) mRNA, tRNA, and rRNA (d) protein (e) mRNA, tRNA, rRNA, and protein
RNA differs from DNA in that the base ________ is substituted for _____________ . (a) adenine; uracil (b) uracil; thymine (c) guanine; uracil (d) cytosine; guanine (e) guanine; adenine
RNA grows in the ______________ direction, as RNA polymerase moves along the template DNA strand in the direction.(a) $5^{\prime} \longrightarrow 3^{\prime} ; 3^{\prime} \longrightarrow 5^{\prime}$(b) $3^{\prime} \longrightarrow 5^{\prime} ; 3^{\prime} \longrightarrow 5^{\prime}$(c) $5^{\prime} \longrightarrow 3^{\prime} ; 5^{\prime} \longrightarrow 3^{\prime}$(d) $3^{\prime} \longrightarrow 3^{\prime} ; 5^{\prime} \longrightarrow 5^{\prime}$(e) $5^{\prime} \longrightarrow 5^{\prime} ; 3^{\prime} \longrightarrow 3^{\prime}$
Which of the following is/are not found in a bacterial mRNA molecule? (a) stop codon (b) upstream leader sequences (c) downstream trailing sequences (d) start codon (e) promoter sequences
Which of the following is/are typically removed from premRNA during nuclear processing in eukaryotes? (a) upstream leader sequences (b) poly-A tail (c) introns (d) exons (e) all the preceding
Which of the following is a spontaneous process, with no direct requirement for ATP or GTP? (a) formation of a peptide bond (b) translocation of a ribosome (c) formation of aminoacyl-tRNA (d) a and b (e) all the preceding
The role of tRNA is to transport (a) amino acids to the ribosome (b) amino acids to the nucleus (c) initiation factors to the ribosome (d) mRNA to the ribosome (e) release factors to the ribosome
Select the steps of an elongation cycle during protein synthesis from the following list, and place them in the proper sequence:1. Peptide bond formation2. Binding of the small ribosomal subunit to the $5^{\prime}$ end of the $\mathrm{mRNA}$3. Binding of aminoacyl-tRNA to the A site4. Translocation of the ribosome(a) $1 \longrightarrow 3 \longrightarrow 2 \longrightarrow 4$ (b) $2 \longrightarrow 3 \longrightarrow 1 \longrightarrow 4$(c) $3 \longrightarrow 1 \longrightarrow 3 \longrightarrow 2$(d) $2 \longrightarrow 1 \longrightarrow 3 \longrightarrow 4$(e) $4 \longrightarrow 2 \longrightarrow 1 \longrightarrow 3$
Suppose you mix the following components of protein synthesis in a test tube: amino acids from a rabbit; ribosomes from a dog; tRNAs from a mouse; mRNA from a chimpanzee; and necessary enzymes plus an energy source from a giraffe. If protein synthesis occurs, which animal's protein will be made?(a) rabbit(b) $\operatorname{dog}(c)$ mouse(d) chimpanzee (e) giraffe
During elongation in translation, the polypeptide chain that is bonded to the tRNA carrying the amino acid most recently added to the chain is in the ____________ site, and an incoming aminoacyl-tRNA attaches to the _________ site. (a) E; P (b) P; E (c) E; A (d) A; E (e) P; A
What is the minimum number of different tRNA molecules needed to produce a polypeptide chain 50 amino acids long but that has only 16 different kinds of amino acids? (a) 50 (b) 25 (c) 20 (d) 16 (e) 8
The statement "the genetic code is redundant" means that (a) some codons specify punctuation (stop and start signals) rather than amino acids (b) some codons specify more than one amino acid (c) certain amino acids are specified by more than one codon (d) the genetic code is read one triplet at a time (e) all organisms have essentially the same genetic code
The ________ catalyzes the excision of introns from pre-mRNA. (a) ribosome (b) spliceosome (c) RNA polymerase enzyme (d) aminoacyl–tRNA synthetase enzyme (e) reverse transcriptase enzyme
A nonsense mutation (a) causes one amino acid to be substituted for another in a polypeptide chain (b) results from the deletion of one or two bases, leading to a shift in the reading frame (c) results from the insertion of one or two bases, leading to a shift in the reading frame(d) results from the insertion of a transposon (e) usually results in the formation of an abnormally short polypeptide chain