Both recessive and dominant characters are found at the same locus of a homologous chromosome. Each chromosome in a pair is inherited from one parent, and the genes located on these chromosomes determine the traits that an individual exhibits.
A gene is a section of DNA that contains the instructions for producing a specific protein or RNA molecule. The locus is the specific location of a gene on a chromosome. In diploid organisms like humans, each locus is present in two copies, one inherited from each parent.
Dominant traits are those that are expressed when at least one copy of the gene is present, while recessive traits are only expressed when two copies of the same gene are present. Therefore, both dominant and recessive characters can be found at the same locus of a homologous chromosome.
For example, in humans, the gene for brown eyes (dominant) and blue eyes (recessive) are found at the same locus on chromosome 15. This means that an individual can inherit one copy of the brown eyes gene from one parent and one copy of the blue eyes gene from the other parent. In this case, the dominant brown eyes gene will be expressed, and the recessive blue eyes gene will be masked.
In summary, both dominant and recessive characters can be found at the same locus of a homologous chromosome, and their expression is determined by the number of copies of the gene an individual inherits.