Agroup of scientists examined a meteorite from mars and found a carbon-rich substance that is produced when microorganisms decay. they concluded that the meteorite provided evidence there was once life on mars. why is this an emerging idea?

Air pollution is only caused by human activity, select the best answer from the choices provided ot of true or false

Which best describes the nucleus of an atom a. it is where all of the particle s of the atom are located b. it is the negatively charged part of the atom c. it is where the electrons and the protons are located d. it is the part of the atom with the greatest mass

Which member of the following food chain will be least affected by ddt, a pesticide water pollutant, if bio-magnification is occurring? algae> zooplankton> crayfish> leopard frog> large mouth bass