Extra / Supplementary Biology
Curious ideas beyond the syllabus, grouped by theme.
Why Do Fingers Wrinkle in Water?Skin soaking up water is not the full story: a finger with nerve damage stays smooth. How the nervous system makes wrinkles, and why their purpose is still debated.Human body · Biology
Why Do We Get Goosebumps?A tiny muscle at the base of each hair, the arrector pili, contracts in cold or fear: the hair stands up and the skin around it rises into a bump.Human body · Biology
Why Do We Yawn?It isn't low oxygen. The leading idea is brain cooling, and yawns are contagious, especially between people who are close.Human body · BiologyNo topic matches. Try a shorter word.