Weather fronts mark the betweel two air masses.

Which of the following correctly list the first appearance of organism in the fossil record from earliest to most recent

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.

Environmental differences within ecosystems are generally caused by