Pedigree analysis

Back cross

Test cross

Dihybrid cross

Genes far apart on the same chromosome show very few recombinations

Tightly linked genes on the same chromosome show very few recombination

Tightly linked genes on the same chromosome show higher recombinations

Genes loosely linked on the same chromosome show similar recombinations as the tightly linked ones

Out of one pair of factors one is dominant, and the other recessive

Alleles do not show any blending and both the characters recover as such in F₂ generation

The discrete unit controlling a particular character is called a factor

Factors occur in pairs

Inheritance of a recessive sex-linked disease like haemophilia

Inheritance of a sex-linked inborn error of metabolism like phenylketonuria

The pedigree chart is wrong as this is not possible

Inheritance of a condition like phenylketonuria as an autosomal recessive trait