<span>When there is no oxygen, or the organism cannot use oxygen for respiration.
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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.
Answer:
Enzymes bring reactants together so they don't have to expend energy moving about until they collide at random. Enzymes bind both reactant molecules, called the substrate, tightly and specifically, at a site on the enzyme molecule called the active site
Explanation: