Question 7 of 15advanced🔧 ApplyShort Answer3 marks
When a cross in made between tall plant with yellow seeds (TtYy) and tall plant with green seed (Ttyy), what proportions of phenotype in the offspring could be expected to be
(a)
tall and green.
Answer
3/8
(b)
dwarf and green.
Answer
1/8
Explanation
This is a dihybrid cross between TtYy (tall yellow) and Ttyy (tall green). Using Punnett square: Parent 1 (TtYy) produces gametes TY, Ty, tY, ty. Parent 2 (Ttyy) produces gametes Ty, ty. The 8 offspring genotypes are: TTYy, TtYy, TTyy, Ttyy, TtYy, ttYy, Ttyy, ttyy. Phenotypic ratio: 3 Tall Yellow : 3 Tall Green : 1 Dwarf Yellow : 1 Dwarf Green. For tall and green (T_yy), proportion is 3/8. For dwarf and green (ttyy), proportion is 1/8.