Answer:
Tundra
Explanation:
Ocean is the most stable biome, provides the majority of earths food and oxygen.
Rainforest provide 20% of earths food production. Also stable.
Grasslands although the don't get much rain it doesn't compare to the harsh weather that Tundra's face.
Tundra's is a very fragile environment. The freezing cold temperatures makes it a very difficult environment to survive in the winter, and plants and animals have a hard time coping with any extra stresses and disturbances. Therefore making it the least stable out of the rest listed.
"An organism in which the two copies of the gene are identical — that is, have the same allele — is called homozygous for that gene. An organism which has two different alleles of the gene is called heterozygous."
Nitrogen fixation would not occur and that would mean that there would be a lack of nitrogen and it wouldn't be able to sustain life. Since nitrogen is an essential element in every amino acid, that also means in every protein. It essential to life and without it life would mostly likely not exist.<span />
They would most likely be a poor metabolizer so D.