Generalized transduction is distinguishable from specialized transduction by the fact that
a. generalized transduction may be used to move any gene, whereas specialized transduction moves only
certain genes.
b. selective medium is required for generalized transduction, whereas selective medium is not required for
specialized transduction.
c. donor DNA must be purified from the donor for generalized transduction, whereas specialized
transduction involves movement of DNA by phages.
d. generalized transduction is possible in generally all organisms, whereas specialized transduction is
possible only in special groups of organisms.
The galactose operon of Escherichia coli is located near the attachment site for the lambda prophage. The
galactose operon
a. codes for enzymes which catabolize galactose
b. can be incorporated into specialized transducing phages
c. can be transferred by conjugation
d. all the above
Specialized transduction
a. is possible only with virulent (also called lytic) phages.
b. depends on reverse transcription.
c. can transfer donor genes only if they are adjacent to prophages.
d. amplifies DNA.
Specialized transduction can be used to transduce the biotin operon from donor to recipient bacteria. Biotin is a
vitamin required for all growth. Suppose that you have a generalized transducing phage preparation which had
been grown on a wild-type biotin+ donor, and a culture of a biotin-requiring mutant recipient. How would you
select transductants?
a. Plate the phage preparation on the recipient host in soft agar to select plaques.
b. Plate the phage preparation on glucose medium.
c. Plate the phage-infected recipient cells on glucose plus biotin medium.
d. Plate the phage-infected recipient cells on glucose without biotin medium.
The simplest plasmid which could be found naturally occurring in bacteria [that is, the smallest plasmid which
would be duplicated in each binary fission cycle and passed on to daughter cells] would consist of a circular:
a. fragment consisting of any random chromosomal gene
b. fragment of DNA containing genes and sites necessary for plasmid replication
c. prophage consisting of the phage repressor gene and phage operators
d. fragment of DNA consisting of the plasmid transfer operon plus the origin of transfer
Properties of Insertion Sequences include:
a. They are linear, double strand DNA molecules.
b. They carry genes for DNA transfer in conjugation.
c. They carry genes for antibiotic resistance.
d. all the above
Plasmids can be used to transform bacterial cells, provided that
a. Restriction enzymes are available.
b. The bacterial cells contain repressor molecules.
c. The plasmids can enter the cells through the cell wall and cytoplasmic membrane.
d. A phage preparation is available.
One of the goals of genomics is to identify every protein coding region of an organism. Assume that the complete sequence of a bacterial chromosome has been determined and that computational support is available to analyze the sequence. What criteria would be useful in finding the genes (protein coding regions) within the chromosome?
a. Genes are expected to be interrupted by introns.
b. Protein coding regions should have a certain minimum number of contiguous codons.
c. Protein coding regions should be adjacent to promoters.
d. All the above are correct.
38. Genomics is used not only to determine the nucleotide sequence of every gene of an organism, but also to determine the function of every gene. The functions of genes discovered by sequencing can sometimes be done by comparing the deduced amino acid sequence of the gene product to the amino acid sequences of known proteins because proteins of similar function often have similar amino acid sequences. Two proteins of very similar amino acid sequence are said to be
a. Orthologous if they are produced by different organisms.
b. Paralogous if they are produced by the same organism.
c. Homologous
d. All the above are correct.
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