Question

The height is under polygenic inheritance the plant having a genotype aabb has 20 cm height plant having genotype AaBbis 50 .cm what is the height of the plant having genotype AaBB

45

65

60

15

Answer 1

Here, minimum height is given i.e 20cm (as all the alleles of aabb are recessive)
Height of plant having genotype AaBb is also given i.e 50cm
​Here, in genotype AaBb, 2 dominant polygenes are present.
We know,
Height of plant = Minimum height + Contribution of dodominant polygene
50 = 20 + (2 x Contribution of each dominant polygene )

Contribution of each dominant polygene = 30/2= 15

Height of plant having genotype AaBB = ​Minm height + Contribution of dominant polygene
= 20 + 3 x 15
= 20 + 45
= 65 cm