Chapter 7 Flashcards
DNA polymerase requires a primer and cannot initiate synthesis de novo. What serves as a primer for DNA replication?
a. Short fragments of DNA complementary to the template strand
b. A protein with a free OH group
c. short fragments of RNA complementary to the template strand
d. The DNA forms a loop resulting in the formation of double-stranded hairpins at the end of the DNA molecule, and these hairpins serve as primers.
c. Short fragments of RNA complementary to the template strand
The DNA sequence to which an RNA polymerase binds to initiate transcription of a gene.is called a(n)
a. enhancer.
b. promoter.
c. polymerase-binding element.
d. origin of transcription.
e. operator.
b. promoter.
Transcription is ___ -dependent ___ synthesis.
DNA;RNA
RNA polymerase I genes code for
a. mRNAs.
b. tRNAs.
c. small nuclear RNAs and small cytoplasmic RNAs.
d. ribosomal RNAs.
e. RNAis
d. ribosomal RNAs
Mitochondrial genes are transcribed by
a. RNA polymerase I.
b. RNA polymerase II.
c. RNA polymerases I and IL
d. RNA polymerase III.
e. a separate mitochondrial RNA polymerase.
e. a seperate mitochondrial RNA polymerase
The first step in forming a transcription complex for mRNA transcription is binding of which of the following to the TATA box?
a. TFIA
b. TFIIA
c. TFIIIA
d. TFIID
e. TFIIB
d. TFIID
A major difference between eukaryotic and prokaryotic RNA polymerases is that eukaryotic polymerases .
a. use a set oftranscription factors to bind to and initiate transcription.
b. use sigma (a) factors to initiate transcription.
c. start from promoters.
d. start from origins of replication.
e. start from enhancers.
a. use a set of transcription factors to bind to and initiate transcription.
Processing of pre-tRNAs to produce tRNAs involves
a. cleavage of the pre-tRNA.
b. CCA addition to the 3’ end.
c. base modification.
d. Both a and c
e. all of the above
e. all of the above
Processing of RNA transcripts occurs
a. only in eukaryotic cells.
b. only with mRNA transcripts.
c. only with;RNA and mRNA transcripts .
d. with tRNA, rRNA, and mRNA transcripts.
e. only in eukaryotic cells and with tRNA, rRNA, and mRNA transcripts.
d. with tRNA, rRNA, and mRNA transcripts.
During splicing, pre-mRNAs go through an intermediate stage when they are shaped like
a. the Greek letter theta (e).
b. a circle.
c. a lariat.
d. a cross.
e. the letter Y.
c. a lariat
Which of the following statements about transcriptional termination in prokaryotes is false?
c. The ribosome comes to a UAA, UAG, or UGA stop codon and transcription ceases.
E. coli preferentially utilize glucose for energy, however, in the absence of glucose, genes that can metabolize alternative sugars are activated. Low glucose
a. activates the i gene that subsequently activates the lac operon, allowing energy to be derived from lactose.
b. activates repressors that bind DNA binding sites of genes that inhibit glucose metabolism, thus raising glucose levels.
c. elevates cAMP through adenylyl cyclase that binds to and activates CAP to effectively
increase transcription rates of genes that metabolize alternative sugars.
d. directly inhibits the activity of RNA polymerase.
c. elevates cAMP through adenylyl cyclase that binds to and activates CAP to effectively increase transcription rates of genes that metabolize alternative sugars.
Eukaryotic RNA polymerase II synthesizes ________
mRNA
Eukaryotic RNA polymerase III synthesizes ________
tRNA
A core promotion element located just upstream from the transcription start site in eukaryotic genes is an A- and T-rich region called the ______
TATA Box
