Gas Exchange and Stomata - KS3 Biology Worksheet

A complete, no-prep 100-mark worksheet on gas exchange and stomata — ready to use for lessons, homework, or revision with KS3 Biology students aged 11-14. Gas exchange is when a photosynthesising leaf takes in carbon dioxide gas and releases waste oxygen gas. It happens through small holes in the surface of the leaf.

Structured across three sections of progressive difficulty: Section 1 (30 marks) covers key facts through 5 multiple choice questions, a 10-statement true or false table and a 10-gap word bank fill-in-the-blank. Section 2 (40 marks) builds understanding through key term definitions, a table showing which way each gas moves, and short answers on guard cells, the waxy leaf surface, diffusion and net movement, the trade-off of opening and closing the holes, thin leaves, and greenhouse growers adding carbon dioxide. Section 3 (30 marks) challenges students with three 10-mark extended answers on cacti opening their stomata at night, a wilting houseplant, and whether leaves should keep their stomata open all the time. A full answer key with detailed marking guidance is included. Comes as a PDF and an editable Word file (DOCX).

Full lesson page with the video, quiz and free worksheet: https://inewittall.com/ks3-biology/gas-exchange-and-stomata/?utm_source=payhip&utm_medium=listing

Watch the full lesson on YouTube: https://youtu.be/tTMSPo6Osec

Also available: a companion extension pack with four enrichment activities, or save £1 with the complete lesson bundle.