7. Homeostasis & Reading Science Data

Homeostasis is the body's ability to keep a stable internal environment even as the outside changes — steady temperature, blood sugar, and water balance.

It works through feedback: a sensor detects a change, and the body responds to push conditions back toward normal. When you get hot, you sweat to cool down; when you get cold, you shiver to warm up. Both responses fight the change — that's negative feedback.

The GED® Science test is as much about reasoning with data as memorizing facts. For any graph or table:

• Read the title, the axis labels, and the units first.
• Find the trend — is the line rising, falling, or steady?
• Use only what the data shows; don't assume causes that aren't supported.

For example, if a graph shows body temperature staying near 37 °C while the room temperature swings from 10 °C to 35 °C, the data is evidence of homeostasis at work.

⚠️ Common misconception: correlation is not causation. Two things rising together does not prove one caused the other.

💡 Tip: on data questions, point to the specific row, bar, or part of the line that supports your answer.