To investigate how the sex of an offspring is determined

Which of the following is true of microbes? a. ninety-nine percent of all microbes are pathogenic. b. gene expression in bacteria is very similar to gene expression in humans, which facilitates the use of bacteria in recombinant biotechnology and gene therapy. c. all bacterial enzymes are harmful to humans and the environment. d. microbes create pollutants and toxins that harm the environment.

20 the compound al(nh3)2 has atoms of nitrogen.

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic