Biomes on earth have exhibited changes throughout history that have been caused by a variety of factors. over the past 50 years, the amount of tropical rainforest acreage found throughout the world has decreased from 14.8 billion acres to 8.6 billion acres due to deforestation. what factor is likely most responsible for the changes observed in the world’s rainforests? a. volcanic activity. b. human activity. c. temperature changes. d. solar eclipses.

b. human activity

Explanation:

A reduction of more than one third the total acreage of tropical forest in the world is not likely to be due to volcanic activity which is not so widespread in the present time. Temperature changes although important, are slow in their effects and are more likely to cause a change in forest cover rather than a dramatic loss. Solar eclipses are not known to cause deforestation. Human activity however, is known to cause important loss in forest acreage due to land use change, mainly to agricultural land.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.