Study Notes
Homeostasis is the process by which organisms maintain a stable internal environment.
- Homeostasis — the regulation of internal conditions to maintain a stable environment. Example: Keeping body temperature constant.
- Excretion — the process of removing waste products from the body. Example: The kidneys filter blood to produce urine.
- Kidneys — organs that filter blood to remove waste and excess substances. Example: They help maintain water balance and remove urea.
- Urea — a waste product formed in the liver from the breakdown of proteins. Example: It is excreted in urine.
- Urine — liquid waste produced by the kidneys. Example: It contains water, urea, and other waste substances.
Exam Tips
Key Definitions to Remember
- Homeostasis
- Excretion
- Kidneys
- Urea
- Urine
Common Confusions
- Confusing excretion with egestion
- Misunderstanding the role of kidneys in homeostasis
Typical Exam Questions
- What is homeostasis? Homeostasis is the regulation of internal conditions to maintain a stable environment.
- How do kidneys contribute to homeostasis? Kidneys filter blood to remove waste and maintain water balance.
- What is the difference between excretion and egestion? Excretion is the removal of metabolic waste, while egestion is the removal of undigested food.
What Examiners Usually Test
- Understanding of how homeostasis maintains stable conditions
- The role of kidneys in filtering blood and producing urine
- Differences between excretion and other processes like egestion