Which statement best summarizes resource distribution on earth?
o
a. all people and cultures have access to the same resources.
o
b. resources are typically only used where they are found.
o
c. resources can be unavailable in areas where they are needed.
o
d. resources are evenly distributed across the planet.

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.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".

the two answers are a, the population of birds with large beaks will increase on the island, and c, the trait for large beaks will be passed on to future generations through natural selection. the reason for that is because if the birds that have beaks developed for eating small seeds lose all of their food, they will go hungry and eventually starve because they physically cannot eat the large seeds, therefore making the population of large beaked birds higher. also, if the trait of large beaks are dominant on the island over small beaks, then over time the large beaked birds will reproduce more and more, while the smaller beaked birds will reproduce less and less because they can't survive with the food provided. that leads to the trait of small beaks disappearing and the trait of large beaks taking over the island.