Episode Details

Because a leaf is trying to make food out of thin air, and the doors it has to open to get that air are the same doors its water escapes through. First we work out the recipe the leaf is cooking. Then we find out what that recipe costs.

The listener realises the oxygen they are breathing right now came out of the same tiny holes a tree loses its water through. A tree on a hot, sunny, windy day is making a choice: eat and get thirsty, or close up and go hungry. They can state the word equation and the path water takes (roots → xylem → leaves → stomata), and name the four factors as 'things that make the bill bigger'.

Sources:

• https://thursd.com/articles/one-of-lifes-most-impressive-phenomenons-stomata-breathing-leaves
• https://link.springer.com/doi/10.1007/BF02880444

Source: Episode 7 - Biology Level 8, How Plants Work (7/10)
Style: Exam prep
Length: 1051 words, 7 min target
Generated: 2026-10-25