1. Selectable marker on a vector helps in the selection of postiively transformed colonies. Some vectors have both a primary and secondary selectable marker for it to be maintained in two different organisms. The use of primary and secondary selectable marker can generate multicopy strains. For example, primary selectable marker may confer antibiotic resistance and a seconday selectable marker may confer resistance to formaldehyde. 2. Conventional PCR and DNA probing both help in the detection of a particular target gene. Conventional PCR uses target specific primers whereas DNA probing uses fluorescently labelled probes which are complementary to the target sequence. Conventional PCR could be non- specific ( the primers could bind to any other complementary regions in the template in addition to the target gene) whereas DNA probing detect only the DNA containing the sequence complementary to the probe; hence, use of the probes increases the specificity in detection. Solution 1. Selectable marker on a vector helps in the selection of postiively transformed colonies. Some vectors have both a primary and secondary selectable marker for it to be maintained in two different organisms. The use of primary and secondary selectable marker can generate multicopy strains. For example, primary selectable marker may confer antibiotic resistance and a seconday selectable marker may confer resistance to formaldehyde. 2. Conventional PCR and DNA probing both help in the detection of a particular target gene. Conventional PCR uses target specific primers whereas DNA probing uses fluorescently labelled probes which are complementary to the target sequence. Conventional PCR could be non- specific ( the primers could bind to any other complementary regions in the template in addition to the target gene) whereas DNA probing detect only the DNA containing the sequence complementary to the probe; hence, use of the probes increases the specificity in detection..

1. 1. Selectable marker on a vector helps in the selection of postiively transformed colonies. Some
vectors have both a primary and secondary selectable marker for it to be maintained in two
different organisms. The use of primary and secondary selectable marker can generate multicopy
strains. For example, primary selectable marker may confer antibiotic resistance and a seconday
selectable marker may confer resistance to formaldehyde.
2. Conventional PCR and DNA probing both help in the detection of a particular target gene.
Conventional PCR uses target specific primers whereas DNA probing uses fluorescently labelled
probes which are complementary to the target sequence. Conventional PCR could be non-
specific ( the primers could bind to any other complementary regions in the template in addition
to the target gene) whereas DNA probing detect only the DNA containing the sequence
complementary to the probe; hence, use of the probes increases the specificity in detection.
Solution
1. Selectable marker on a vector helps in the selection of postiively transformed colonies. Some
vectors have both a primary and secondary selectable marker for it to be maintained in two
different organisms. The use of primary and secondary selectable marker can generate multicopy
strains. For example, primary selectable marker may confer antibiotic resistance and a seconday
selectable marker may confer resistance to formaldehyde.
2. Conventional PCR and DNA probing both help in the detection of a particular target gene.
Conventional PCR uses target specific primers whereas DNA probing uses fluorescently labelled
probes which are complementary to the target sequence. Conventional PCR could be non-
specific ( the primers could bind to any other complementary regions in the template in addition
to the target gene) whereas DNA probing detect only the DNA containing the sequence
complementary to the probe; hence, use of the probes increases the specificity in detection.