Some types of bacteria can reproduce every 20 minutes under ideal conditions. if a single bacterium begins to reproduce at this rate, what is the best estimate of how many bacterial cells there will be after 80 minutes?
8
16
40
80

If many different species live in an ecosystem, this the ecosystem to fill its a. populations b. niches c. producers d. communities

25) a student takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are: liquid a: the solid dissolves quickly. liquid b: the solid appears unchanged. liquid c: a brownish colored liquid is produced. liquid d: fizzing occurs and the well becomes warmer. in which well does a physical change occur?

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above