Biology 3 - Regulating the human and natural environments

Animals need to regulate their internal environment by getting rid of wastes like urea and carbon dioxide, and maintaining constant internal conditions.

Homeostasis is the process where animals maintain constant internal levels for body temperature, water, ions, and sugar.

The kidney is an organ that filters wastes like urea from the blood and regulates the levels of water and ions in the blood.

Kidney failure leads to a build-up of toxic wastes like urea, which can be fatal.

Kidney transplants replace the damamged kidney but the transplanted kidney must be matched by tissue typing, to avoid rejection.

The skin is the organ involved in temperature control.

Overheating is prevented by sweating, haires lying flat, and vasodilation.

Overcooling is prevented by shivering, insulation, and vasoconstriction.

Blood glucose levels are controlled by the hormones insulin and glucagon.

Diabetes is a condition where insulin is not made, resulting in a failure to control the blood glucose level.

The human population is increasing, which is putting extra demand on the Earth's resources.

Humans release pollutants into the air and water from agriculture, towns, and industry.

Deforestation is the process of removing large areas of natural woodland.
This can result in an increase in carbon dioxide levels in the atmosphere, and loss of habitat.

Carbon dioxide, and methane from rice fields and cattle, are greenhouse gases that lead to global warming.

Biofuels are fuels from biological materials, which do not contribute to global warming.

Humans are increasing food production to feed the increasing population by producing protein foods from fungi like mycoprotein.

Farming methods can be made energy efficient by reducting energy losses in food chains.

Overfishing had led to dwindling fish stocks.
Governments introduced quotas and changes to nets to prevent overfishing.