If you start with a single bacterium, capable of dividing every 20 minutes, how many bacteria would you have after just 4 hours

Last week i was assigned a thematic. we have groups of three but the people i was assigned with haven't been in school for days. i would appreciate if anyone can me with my thematic . i highlighted most of the important steps and i circled my thematic topic. in desperate need : ( its due on february 19

When analyzing tree rings, what do scientists assume a thin ring indicates?

If assuming tasting ptc as a simple gene trait, what other genotype would you select to put in this missing genotype box that could result in this phenotype