The observer-expectancy effect describes how a) a participant in a study might consciously influence the researcher of an experiment. b) a participant in a study might unconsciously influence the researcher of an experiment. c) a researcher's bias might cause him to influence the participants of an experiment purposely. d) a researcher's bias might cause her to influence the participants of an experiment unconsciously.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

population. population is the number of people or animals in a particular place. an example of population is over eight million people living in new york city.

here is your answer hope i .