Under which of the following circumstances would the allele frequencies of two populations be very different?
O A. If there is a large amount of gene flow
B. If the selective pressures are different
C. If the populations have healthy reproductive rates
O D. If there is a large amount of genetic drift

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.