Many of the quantitative methods discussed are popular because they enable the microbiology researcher to selectively count live cells only. Why do you think this might be an important or desirable feature in a medical or environmental research situation? Provide a scenario in which it might not be important to differentiate between live and dead cells when counting cell numbers.

to count cancer cells killed during chemotherapy

Explanation:

There are different methods for counting live cells and they include, among others, counting chambers (e.g., a hemocytometer), image analysis, flow cytometry, spectrophotometric techniques, impedance detection, etc. These laboratory techniques can be used to detect both live and dead cells. In flow cytometry, for instance, it is possible to detect death cells by analyzing the loss of membrane integrity, which is an indicator of death. However, in certain situations, is not required to differentiate between live and dead cells, and thus it is only required to know the number of cells that a sample contains (for example, for counting the number of immortalized cells cultured over several generations).

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation: