The Discovery of Penicillin

Teach cause and effect with a true story students will remember: how a messy laboratory and a drifting mold spore led to one of the most important discoveries in medicine. This scaffolded reading passage follows Alexander Fleming and the accidental discovery of penicillin as a clear chain of causes and effects.

After reading, students complete a cause-and-effect chain organizer. They trace how each event led to the next, then sort a direct (immediate) effect from an indirect (long-term) effect of the discovery. The causal links in the passage are mostly implied rather than flagged with signal words, so students have to reason about how events connect instead of hunting for “because” and “so.”

This resource is perfect for close reading, science reading, sub plans, homework, early finishers, and small-group work. It pairs a high-interest science topic with an essential reading skill, so it earns its place twice in your week.

Includes a print-ready PDF passage, a full-page graphic organizer, and a complete answer key with sample responses. Aligned to CCSS RI.6.3. Just print and teach.