When we look at a population, we see that an individual trait may have multiple phenotypes due to variation in the type of protein produced

When we look at a population, we see that an individual trait may have multiple phenotypes due to genetic variation in the type of protein produced.

Explanation:

The phenotype constitutes the observable traits of an individual, such as height, eye color, and blood group. The genetic contribution to the phenotype is called genotype. Some traits are largely determined by genotype, while other traits are largely determined by environmental factors. Genetic variation is the raw material from which the diverse populations of a species adapt to changes in their environment. New genetic variations arise within populations from spontaneous mutations of a gene or by immigration of individuals from genetically distinct populations. Each chromosome contains many genes, the basic functional and physical units of genetic inheritance. Genes are specific sequences of the bases that encode instructions to form proteins. The DNA sequence is the specific longitudinal arrangement of the bases in the DNA chain. Each gene has a specific DNA sequence. From a common heritage that is the gene endowment of each cell, identical in all of them, the endowment has diverse mechanisms that make it possible to express it differently in each cell and in each individual. That is, although the genetic code and the systems for decoding are basically universal, there are complex differential regulation phenomena that constitute the basis by which each individual responds differently to the environment, and by which each living cell is identified, that is , that the action of a gene, then, is subject to multiple influences external to it, capable of modifying its expressive capacity from the first step, the transcription, to the last, the post-translational transformation of the protein.

the correct option is option d