The heterozygous parent can produce two types of gametes one having T allele and or having t allele. However, second parent being homozygous can produce only one type of gamete having t allele. Random mixing of se gametes will produce following progeny:
Tt one half total number of progeny.
tt one half total number of progeny.
This cross is a typical Mendelian test cross.

Theodore Boveri and Walter Sutton had unraveled mechanisms underlying chromosome movement during cell division. These movements were correlated with Mende?s laws.