The andswer to the question is Endocrinology!
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.
Urine forms as some of the blood plasma spills out, some of these spilled plasma components are taken back up into the blood, and other material is selectively sent out to be added to the urine. In other words, there are three main things happening to form urine.
glomerular filtration (blood plasma spills out) bullet tubular reabsorption (some items are selectively reabsorbed into the blood) bullet tubular secretion (some blood plasma items are selectively sent out into the tubules)
All I can think of is glucose
