WAEC - Biology (2004 - No. 55)
Heterozygous tall plants were crossed with pure-breeding dwarf plants of the same species. What were the approximate percentages of the offspring?
100% tall 0% dwarf
75% tall 25% dwarf
50% tall 50% dwarf
25% tall 75% dwarf
Explanation
A heterozygous tall plant (say Tt) crossed with pure-breeding dwarf plants (tt) will give a set of Tt, Tt, tt and tt. This is 50% tall and 50% dwarf approximately.