How does the current, or sixth, mass extinction differ from the past five mass extinction events?
a.
the sixth mass extinction is believed to be caused by human-related factors.
b.
the sixth mass extinction is believed to be caused by natural forces.
c.
the sixth mass extinction is believed to affect relatively fewer species.
d.
the sixth mass extinction is believed to affect relatively fewer areas.

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.

the rocks are classified by the geological process they are formed by. the three main groups of rocks are igneous, metamorphic, and sedimentary. minerals are not they are classified under the chemical classes they are in. these groups include silicates, sulfates and carbonates.

the two new cells are called daughter cells