Two pink coloured flowers on crossing resulted in 1 red, 2 pink and 1 white flower progeny. The nature of the cross will be (a) double fertilisation (b) self pollination (c) cross fertilisation (d) no fertilisation

explain answer with reason

Dear Student,
The nature of the cross will be cross fertilisation. Fertilising a plant using pollen from another plant of the same species is cross-fertilisation.
Let the genotypes of the pink flowers be Rr where R codes for red colour and r for white colour (when homozygous recessive). The R allele is not completely dominant over the other allele. This is an example of incomplete dominance.
Parents  Rr (pink)   ×    Rr (pink) 
Gametes R, r                 R, r
selfing                 ↓  

F1 RR (Red)  Rr (pink)  Rr (pink)  rr (white)

​​​Incomplete dominance refers to the phenomena in which neither of the traits are able to completely dominate the other. This leads to the partial expression of both the traits. An example of this is Mirabilis  jalapa. When pure breeding white flowers are crossed with pure breeding red flowers then we get all pink flowers in F1 generation. 


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