Answer:
Each parent had at least one allele for white petals.
Explanation:
According to the law of inheritance, it is necessary that each offspring must inherit one allele from each of its parents for a given gene.
Since in the given question, a rose plant inherits a white flower petal allele, it is necessary that the plant must have an inherited one allele from each parent, therefore, the two parents must have had at least one allele for white petal.
The cross is shown below ,
W---> red petal
w ----> white petal
<u>Atleast one allele</u> => Ww X Ww ---> WW Ww Ww ww
<u>More than one allele</u> => ww X ww ----> ww
Here ww is the offpsring with white petals.
