Whether you inherit a condition depends on its pattern. Does it take one faulty allele or two? And does it sit on a regular chromosome or on the X? Click each pattern to see its rule and its classic conditions.
The alleles you need
A capital letter is the dominant allele. A lowercase letter is the recessive one. Red marks an affected genotype.
Pick a pattern.
Pick a patterndominant · recessive · X-linked
The rule
Key terms
Homozygous
two of the same allele (BB or bb)
Heterozygous
mixed alleles (Bb), one dominant and one recessive