NEET2016ZoologyPrinciples of Inheritance and VariationActual
In a testcross involving F 1 dihybrid flies, more parental-type offspring were produced than the recombinant-type offspring. This indicates:
Options
- AThe two genes are located on two different chromosomes
- BChromosomes failed to separate during meiosis
- CThe two genes are linked and present on the same chromosome
- DBoth of the characters are controlled by more than one gene
Correct answer
C. The two genes are linked and present on the same chromosome
Step-by-step solution
If a plant with genotype AaBb is crossed with that with aabb, then independent assortment would result in the production of 4 types of offsprings in equal proportion. AaBb - gametes: AB Ab aB ab Aabb - gametes: ab ab ab Offspring according to independent assortment: AaBb Aabb aaBb aabb 1 : 1 : 1 : 1 (Parental) (Recombinants) (Parental) Since parental percentage is more than recombinants, it is due to linkage between genes A and B.