Final answer:
An inherited feature that varies from individual to individual is described as an allele, which is a different version of a gene. Alleles determine an individual's genotype and consequently their phenotype, resulting in the observable variation in traits within a population. The correct option to describe this feature is Option 1: Allele.
Step-by-step explanation:
An inherited feature that varies from individual to individual can be manifested in various forms, depending on the genetic makeup of an organism. In genetics, this variability is largely attributed to the concept of alleles. Alleles are different versions of a gene, which are found at the same locus on a chromosome and can result in diverse traits within a species. For every gene, a diploid organism (an organism with two sets of chromosomes, such as humans) inherits two alleles, one from each parent.
The combination of alleles an individual has is known as their genotype, which can be homozygous (both alleles are the same) or heterozygous (two different alleles). An individual’s genotype is pivotal in determining their phenotype, which is the set of observable characteristics of an organism, like eye color or height. Notably, when a gene has two alleles, and one is dominant while the other is recessive, the phenotype will be influenced by the dominant allele unless the organism is homozygous for the recessive allele.
Gregor Mendel's pioneering work on heredity established the foundational principles for our understanding of how traits are inherited. Mendel observed that certain traits are expressed in predictable ratios in the offspring, thus helping to uncover the basic laws of inheritance. Today, we recognize these hereditary 'factors' as alleles, and population genetics continues the study of how these alleles are transmitted through generations and how they affect entire populations.
In conclusion, the correct option that describes an inherited feature that varies from individual to individual is Option 1: Allele. Alleles are the different versions of a gene responsible for the variation in traits observed among individuals in a population.