Question

A breeder crossed a pure bred tall plant having white flowers to a pure bred short plant having blue flowers. He obtained 202 F₁ progeny and found that they are all tall having white flowers. Upon selfing these F₁ plants, he obtained a progeny of 2160 plants. Approximately, how many of these are likely to be short and having blue flowers?

(a) 1215

(b) 405

(c) 540

(d) 135

Answer 1

Answer is : (d) 135

According to dihybrid phenotypic ratio

9 : 3 : 3 : 1,

TW — 9

Tw — 3

tW — 3

tw — 1

The total number of short and blue flowered plants is

1/16 x 2130 = 1080/8 = 135