Which statement could be a possible explanation for the drop in mercury concentration in the fish of
onondaga lake between the years 2002 and 2003?
(1) between 2000 and 2005, a large number of fish were sampled.
(2) the dumping of industrial waste was prohibited in 2004.
(3) more young fish were tested in 2003, compared to the other years.
(4) the industrial waste contained more mercury in 2004.

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.

Autotrophs a. consume their food to get energy b. may use photosynthesis to gain energy c. are also called consumers d. cannot use solar energy

(drag each tile to the correct location.) categorize each term as something that is typical of a scientific theory, a scientific hypothesis, or both. - a tentative statement used to guide scientific investigations. - makes predictions about future events. - can be tested by many independent researchers. - based on observations of natural phenomena. - a well-established, highly reliable explanation.