Mendel’s success was based on making good choices: 1. Used a self-fertilizing plant (the garden pea) 2. Chose traits that had clear cur alternative forms (7 traits) 3. Started his experiments with pure-breeding lines 4. Did reciprocal crosses to eliminate maternal effects 5. Analyzed a large number of plants (quantitative analysis) 6. All plants were planted under same conditions

Monohybrid crosses: Disappearance of the recessive trait in F1 Reappearance of the recessive trait in F2 Body cells carry two alleles for each gene Reproductive cells (sperm or an egg) carry only one allele of each gene