Genetics urgent

Asked by baidshryans | 27th Feb, 2009, 12:16: AM

Expert Answer:

Tall plant with red flowers                     Dwarf plant with white flowers

        TTRR                                                                     ttrr ........................  Parents

           ↓                                                                           ↓

          TR                                                                          tr    .......................   Gametes

a) These gametes on fusion gives TtRr plants in the F1 generation. Their phenotype will be tall plants with red flowers.

 

b) The gametes obtained by selfing the plants of F1 are:  TR, Tr, tR, tr

 

c) On crossing these gametes,

 

                 

 

TR

Tr

tR

tr

TR

TTRR (Tall plant red flowers) TTRr (Tall plant red flowers) TrRR (Tall plant red flowers) TtRr (Tall plant red flowers)

Tr

TTRr (Tall plant red flowers) TTrr (Tall plant white flowers) TtRr (Tall plant red flowers) Ttrr (Tall plant white flowers)

tR

TtRR (Tall plant red flowers) TtRr (Tall plant red flowers) ttRR (Dwarf plant red flowers) ttRr (Dwarf plant red flowers)

tr

TtRr (Tall plant red flowers) Ttrr (Tall plant white flowers) ttRr (Dwarf plant red flowers) ttrr (Dwarf plant white flowers)

 

So the ratio of plants in F2 generation is 9 (Tall plant red flowers) : 3 (Tall plant white flowers) : 3(Dwarf plant red flowers) : 1 (Dwarf plant white flowers)

Answered by  | 27th Feb, 2009, 11:17: AM

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