751. Catabolite activating protein exerts __________ control on transcription of the lac operon genes.
A. positive
B. negative
C. may be positive or negative
D. none of these
752. DNA is methylated at
A. AC sequences
B. TATA sequences
C. CAAT sequences
D. CG sequences
753. Why are several structural genes regulated as a unit in bacteria?
A. An accident of evolution
B. It allows coordinating regulation of genes with a common function
C. The bacteria chromosome is so small; many different genes must be controlled by the same promoter
D. none of the above
754. Alternate splicing of RNA transcripts is a mechanism to regulate
A. tubulin
B. tachykinins
C. DNA methylation
D. leucine zippers
755. The viruses that can achieve neoplastic transformation are called
A. DNA tumor viruses
B. RNA tumor viruses
C. retroviruses HIV
D. none of these
756. For gene transfer to be effective, transforming DNA must be
A. incorporated into the bacterial chromosome
B. incorporated into a viral genome
C. free in the bacterial cytoplasm
D. none of the above
757. Double stranded DNA denaturation with specified limit of temperature is
A. reversible reaction
B. irreversible reaction
C. either (a) or (b)
D. none of these
758. From a single molecule of DNA, PCR can make
A. one additional copy
B. hundreds of copies
C. thousands of copies
D. millions of copies
759. Genomic libraries are made from
A. genomic DNA of an organism
B. genomic RNA of an organism
C. genomic cDNA of an organism
D. genomic mRNA of an organism
760. Bacteriophages are
A. cells in the blood that eat bacteria
B. a class of bacteria
C. bacterial viruses
D. none of the above