Which among the following factor is responsible for the phenotype of an organism ?

Genotype

The correct answer is Option (3) –Genotype

Phenotype: The phenotype is the physical expression of the genetic information in the genotype. It includes traits such as eye color, height, and other observable features. The phenotype results from the interaction between the genotype and environmental factors.

• Genotype: The genotype of an organism refers to its genetic makeup, which includes the combination of alleles present in its DNA. These alleles determine the traits or characteristics that an organism inherits from its parents. The genotype influences the phenotype—the observable characteristics or traits of the organism.
• Linkage: Linkage refers to the tendency of certain genes to be inherited together because they are located close to each other on the same chromosome. While linkage can influence the inheritance of traits, it is not the factor directly responsible for the phenotype. The phenotype is more directly influenced by the specific alleles present in the genotype.
• Nutrition: Nutrition can affect aspects of the phenotype, particularly in terms of growth, development, and overall health. However, nutrition is an environmental factor that interacts with the genotype to influence the phenotype.
• Mutation: Mutations can alter the genotype, and depending on the nature of the mutation, they can influence the phenotype. Mutations can introduce new variations and traits in a population, contributing to the diversity of phenotypes.

In summary, while factors such as linkage, nutrition, and mutations can play roles in shaping the phenotype, the primary factor responsible for the phenotype is the genotype—the genetic information inherited from the organism's parents.