* If a population of 100,000 microbes was treated with anbactericidal chemical solution for two minutes and 90% of thepopulation dies per minute, how many microbes remain after twominutes?
a. 100,000
b. 10,000
c. 1000
d. 100
*We wished to determine the abundance of bacteria in a sample ofmilk. To do this ten-fold serial dilutions of a one milliliter milksample were prepared. One milliliter of the fourth 10-fold serialdilution was plated in a pour plate. After incubation, the platehad 35 colonies. How many bacteria were in the original milksample?
a. 35 cells per ml
b. 350 cells per ml
c. 3,500 cells per ml
d. 35,000 cells per ml
e. 350,000 cells per ml
*According to our present understanding, each of the three majordomains of organisms has what is known as its own universalancestor.
a. True
b. False
*Both environmental conditions and nutrient resources stronglyinfluence the composition of a microbial community.
a. True
b. False
