Chaperones mediate nucleosome assembly. From the list below, what must happen first?
A. The CAF-1 chaperone binds an H3-H4 dimer and deposits it onto the DNA strand.
B. H3 and H4 form heterotetramers.
C. The NAP-1 chaperone assembles two H2A-H2B heterodimers with a H3-H4 tetramer.
D. The CAF-1 chaperone binds an H2A-H2B dimer and deposits it onto the DNA strand.
A B cell CstF-64 mutant will likely:
A. constitutively secrete IgM antibodies.
B. selectively remove the VDJ region from IgM antibodies.
C. cut IgM pre-mRNA at every available 3'-end cleavage site.
D. undergo IgM pre-mRNA splicing between the heavy chain exons and the membrane anchoring exon.
Which of the following is not true of genomic and cDNA libraries?
A. Genomic libraries contain fragments of genomic DNA that are generated by partial digests with restriction enzymes.
B. cDNA libraries contain cDNAs made from mRNA.
C. cDNA libraries only contain sequences from transcribed genes.
D. Genes represented in cDNA libraries contain control sequences that direct transcription.
E. Genomic libraries usually contain large fragments and are likely to be constructed in YAC or BAC vectors.
A northern blot could be used best to monitor control of gene expression at which of the following steps?
A. DNA methylation
B. nucelosome acetylation
C. protein ubiquitination
D. transcription
Polyglutamine (polyQ) diseases:
A. result from template slippage during replication.
B. result when CAG repeats increase above the disease threshold.
C. is a triple expansion disease.
D. include Huntington disease and fragile X syndrome.
E. All of the statement choices are correct.
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