Question

Is it possible for a cross of two green parakeets to produce a white parakeet? How would this work?

Answer 1

Yes, it is possible that when two green parakeets are crossed, a white parakeet can be produced. In the type of parakeets called as budgie, two autosomal genes are located on different chromosomes that control the production of feather pigment. A yellow pigment is synthesized under the control of the dominant gene Y. The birds which are homozygouus for recessive y do not produce any yellow pigment.

Gene B codes for an enzyme that is required for the synthesis of a blue pigment. Birds who are homozygous for recessive b do not produce blue pigment.

The parakeets who produce both yellow and blue pigments will have a green feather colour, those who have Dominant Y or B genes will have yellow or blue coloured feathers respectively, and those that do not produce any pigment will be albino(no pigmentation or white colour)

For the offsprings to become white or albino, both the parents should be heterozygous, that is, having the genotype as BbYy. When two parents having this genotype are crossed, one offspring will have the genotype which is bbyy, which will produce the albino or white feathered bird.