question_answer

When a cross is made between tall plant yellow seeds (TtYy) and tall plant with green seed (Ttyy), what proportion of Phenol type in the offspring could be expected to be:

(i)   tall and green         (ii) dwarf and green

OR

In peas, tallness is dominant over dwarfiiess, and red colour flowers is dominant over the white colour. When a tall plant bearing red flowers was pollinated by a dwarf plant bearing white flowers, the different phenotypic groups were obtained in the progeny in numbers, mentioned against them.

(i) Tall, Red = 138

(ii) Tall, White = 132

(iii) Dwarf, Rdd = 136

(iv) Dwarf, White = 128

 

Answer:

OR

The result shows that the four types of offsprings are in a ratio of 1 : 1 :1 :1. Such a result is observed in test-cross progeny of a dihybrid cross.

The cross can be represented as:

Tall and red (Tt Rr) \[\times \] Dwarf and White (ttrr)

Genotype of two patrents - TtRr, ttrr.