In chickens, there is a mutant gene called ʺfrizzleʺ that results in weak, stringy, and easily broken feathers. When a frightfully frizzled fowl is bred to a normal chicken, the offspring are all mildly frizzled. If one breeds two mildly frizzled chickens to each other, the offspring have the phenotypic ratio of 1 normal: 2 mildly frizzled: 1 frightfully frizzled. What is the mode of inheritance of ʺfrizzleʺ?

codominance

Explanation:

The mode of inheritance of frizzle is codominance.

In codominance mode of inheritance, the two alleles representing a gene exert equal effects on ech other. Both alleles contribute equally to the phenotypic (physical appearance) expression of the gene.

For example, if A and B represent alleles of the same gene that are codominant over one another, instead of A or B to be expressed in the phenotype (if A or B is dominant), AB will be expressed.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.