Chapter 16 Flashcards
A DNA sequence, which can be distant from the gene, stimulates transcription when bound by a protein. This sequence is called a(n)
A. TATA box.
B. operon.
C. enhancer.
D. promoter.
E. consenses sequence.
D
Ubiquitin forms a complex with proteins and then binds with ___, forming a sort of “molecular chamber of doom,” where proteins are digested into small peptides and amino acids.
A. the extracellular space
B. mitochondria
C. the proteasome
D. lysosomes
E. the Golgi apparatus
C
Which of the following statements about TATA boxes is false?
A. They bind a specific transcription factor.
B. The are found in the region of the promoter.
C. They are part of the intron consensus sequence.
D. They help specify the starting point for transcription.
E. They contain thymine-adenine base pairs.
C
The three basic parts of a prokaryotic operon are the
A. promoter, the operator, and two or more structural genes.
B. promoter, the structural genes, and the termination codons.
C. promoter, the mRNA, and the termination codons.
D. structural genes, the mRNA, and the tRNAs.
E. None of the above
A
Alternative splicing helps to explain
A. the small number of genes int he human genome.
B. the differences in complexity among organisms.
C. why there are more mRNAs than human genes.
D. the great variety in proteins.
E. All of the above
E
DNA methylation
A. is a mechanism of gene inactivation.
B. adds methyl groups to cytosine residues in certain genes.
C. inhibits transcription.
D. Both a and b
E. All of the above
E
A promoter is the region of
A. a plasmid that binds the enzymes for replication.
B. the mRNA that binds to a ribosome.
C. DNA that binds RNA polymerase.
D. the mRNA that binds tRNAs.
E. None of the above
C
In mammals, a cell that contains three Barr bodies will necessarily have
A. three Y chromosomes.
B. three X chromosomes.
C. four Y chromosomes.
D. four X chromosomes.
E. three nuclei.
D
It is found that a certain enzyme is synthesized whenever the solution is which the cells are growing contains substance X. This phenomenon is most likely an example of ___ gene regulation.
A. positive
B. inducible
C. repressible
D. negative
E. positive-negative
B
Expression of some eukaryotic genes can be regulated by translational control. One advantage of translational control is that is
A. provides a means for rapid change in protein concentrations.
B. prevents synthesis of excess RNA.
C. directs proteins to their proper subcellular location.
D. occurs only in zygotes.
E. degrades proteins that are no longer needed.
A
Transcription factors are
A. RNA sequences that bind to RNA polymerase.
B. DNA sequences that regulate transcription.
C. proteins that bind to the DNA promoter sequence.
D. polysaccharides that bind to the transcripts.
E. factors that bind to enhancers.
C
Catabolite repression refers to the
A. increased transcription from many operons when flucose is present in the medium.
B. shutdown of transcription from many operons when glucose is present in the medium.
C. increased activity of inducers caused by glucose in the medium.
D. Both a and b
E. Both a and c
B
Gene expression can be regulated
A. before transcription.
B. during transcription and before translation.
C. during translation.
D. after translation.
E. All of the above
E
Nucleosomes disaggregate to allow transcription and then reaggregate
A. through alternative splicing.
B. by acetylation and deacetylation.
C. through alternation of nucleotides.
D. by attaching ubiquitin.
E. through insertion of nucleotides.
B
