In a plant, the red colour of the flower is dominant over white. A cross was made between a plant containing red flower and other with white flower. The cross yielded 50% white-flowered plant and 50% red flowered plant. The trait of the parent with the red flower has:
In a plant, the red colour of the flower is dominant over white. A cross was made between a plant containing red flower and other with white flower. The cross yielded 50% white-flowered plant and 50% red flowered plant. The trait of the parent with the red flower has:
The correct option is B Heterozygous
White colour is due to recessive genees, hence white flowered plant will always have a combination of 'rr'. Two possible combinations are possible for the plant with red coloured flowers i.e. RR and Rr. We will examine both the cases.
Case I:
Parents Red flower X White flower
RR X rr
Gametes R X r
F1 generation: Rr (All red flowers)
But the result says 50% of the flowers were red and remaining 50% were white. So, this cannot be the case of parental combinations.
Case II
Parents: Red flower X White flower
Rr X rr
Gametes R and r X r
F1 generation: Rr (red flowers) and rr (white flowers)
These results match the given results and hence the above parental combination is correct. Therefore, the combinational trait of the red flowered plant is Rr.i.e, dissimilar or different alleles.
Heterozygous
White colour is due to recessive genees, hence white flowered plant will always have a combination of 'rr'. Two possible combinations are possible for the plant with red coloured flowers i.e. RR and Rr. We will examine both the cases.
Case I:
Parents Red flower X White flower
RR X rr
Gametes R X r
F1 generation: Rr (All red flowers)
But the result says 50% of the flowers were red and remaining 50% were white. So, this cannot be the case of parental combinations.
Case II
Parents: Red flower X White flower
Rr X rr
Gametes R and r X r
F1 generation: Rr (red flowers) and rr (white flowers)
These results match the given results and hence the above parental combination is correct. Therefore, the combinational trait of the red flowered plant is Rr.i.e, dissimilar or different alleles.
