I believe the biosphere is fragile, because over time all of the pollution us humans have made; If its from air pulloution, acid rain or even water pollution. the toxic acids over time have made the biosphere and the ozon layer weaker and more thin. which causes the biosphere to become weaker.
The answer is: Chloroplasts.
Latitude and ocean currents are the ones i know.
Answer: The hepatic portal vein is one of the most important vein that receives blood from the body and transports it into the liver for filtration and processing. This vein is part of the hepatic portal system that receives all of the blood draining from the abdominal digestive tract, as well as from the pancreas, gallbladder, and spleen.
‘Hepatic’ means of or relating to the liver, therefore the hepatic portal vein is a blood vessel that sends nutrient-rich blood from the gastrointestinal tract and spleen to the liver, but also delivers toxins to the liver that will be chemically modified in the proces of detoxication