1. Ask a question: He thought how traits passed from one generation to another.
2. Form a hypothesis: His hypothesis was "Each plat has two factors for a trait, one from each parent.
3. Test hypothesis: He grew pea plants to see what will happen.
4. Make and record observations: He discovered that one factor alone doesn't determine the expression of the trait in the pea plant.
5. Conclusion: Traits in pea plants are inherited from the parent pea plants.