the work of mendel

• gregor mendel was an austrian monk who studied genetics using pea plants
• mendel reached three important conclusions: characteristics are determined by 'hereditary units' ; hereditary units are passed onto offspring unchanged from both parents ; hereditary units can be dominant or recessive
• dominant traits always appear when they are present in either parent (either homozygous or heterozygous)
• recessive traits only appear if two copies of that allele are present (homozygous)