1. A graduate student is trying to identify the gene coding for an enzyme found in a bacterial species that degrades trinitrotoluene (TNT). The student is frustrated to find that the organism does not produce the enzyme when grown in nutrient broth, making it difficult to collect the mRNA needed to help identify the gene. What could the student do to potentially increase the amount of the desired enzyme?

2. You are a student working in a research lab. You isolate a multidrug resistant strain of bacteria from a hospital's intensive care unit. Your multidrug resistant strain can grow in the presence of penicillin, streptomycin, and chloramphenicol. When you mix your multidrug resistant strain with bacteria sensitive to the three antibiotics, you notice that the previously sensitive strain is now resistant to penicillin and chloramphenicol, but not streptomycin. How can you describe these results?

3. why would the sequence of ribosomal RNA genes remain relatively stable over time?

4. An effective DNA probe can sometimes be developed by knowing the amino acid sequence of the protein encoded by the gene. A student argued that this is too time-consuming since the complete amino acid sequence must be determined in order to create the probe. Does the student have a valid argument? Why or why not?