Describe the role a microbiologist and a medical laboratory technician would play in solving this case of the unknown bacteria.

The unknown bacteria can be identify through the expertise of a microbiologist based on cell and colony morphology, chemical composition of cell walls and biochemical activities of bacteria.

Moreover, the medical laboratory technician perform the different procedures such as gram stain, culture and sensitivity procedure and biochemical tests, which are the most definitive way to identify bacterial species to help the microbiologist in the  bacterial identification and give assessment based on the results.

they float because they are less dense than the water itself

something denser than water, like a rock, will sink to the bottom

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.