The Concept of Homeostasis in Biology

Reading Passage

Homeostasis refers to the ability of living organisms to maintain a stable internal environment despite external changes. This concept is crucial in biology as it ensures the proper functioning of cells and organs. For example, humans regulate their body temperature, blood pH, and glucose levels through various mechanisms. These processes involve feedback systems that detect deviations from normal conditions and trigger responses to restore balance. Homeostasis is essential for survival, allowing organisms to adapt to environmental fluctuations and maintain optimal conditions for cellular activities.

Listening Transcript

Alright, let's talk about homeostasis by looking at two examples. First, consider how our bodies regulate temperature. When it's hot outside, we sweat. Sweating is the body's way of cooling down. The evaporating sweat takes heat away from the skin, helping to lower body temperature. Conversely, when it's cold, we shiver. Shivering generates heat through muscle activity, which helps to warm the body up. Another example is blood sugar regulation. After you eat, your blood sugar levels rise. In response, the pancreas releases insulin, which helps cells absorb glucose, lowering blood sugar back to normal. If blood sugar gets too low, the pancreas releases glucagon, prompting the liver to release stored glucose into the bloodstream. Both these processes illustrate how homeostasis keeps our internal conditions stable.

Speaking Task Instruction

Explain the concept from the reading and use the professor’s examples to show how it works. Preparation time: 30 seconds, Response time: 60 seconds.

Sample Student Response

Homeostasis is the process by which organisms maintain a stable internal environment. In the reading, it describes how this is important for the functioning of cells and organs. The professor gives the example of body temperature regulation. When it's hot, we sweat to cool down, and when it's cold, we shiver to warm up. This shows how our body keeps temperature constant. Another example is blood sugar control. After eating, insulin lowers blood sugar, while glucagon increases it when needed. These examples show how homeostasis helps keep our body's internal conditions stable, which is essential for survival.