A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes): Chromosome 1 RNMDHBGKWU Chromosome 2 RNMDHBDHBGKWU What term best describes this situation?

Key Concepts

Homologous Chromosomes

Homologous chromosomes are pairs of chromosomes in a diploid organism that have the same structure and gene sequence but may carry different alleles. Each parent contributes one chromosome to the pair, resulting in genetic variation. In the context of Drosophila, these chromosomes can carry genes that influence traits, and their comparison can reveal important genetic relationships.

Alleles

Alleles are different versions of a gene that can exist at a specific locus on a chromosome. They can be dominant or recessive, influencing the phenotype of an organism. In the given example, the presence of different alleles on the homologous chromosomes indicates genetic variation, which is crucial for understanding inheritance patterns and traits in Drosophila.

Genetic Variation

Genetic variation refers to the diversity in gene frequencies among individuals within a population. It is essential for evolution and adaptation, as it provides the raw material for natural selection. The differences in the gene sequences of the homologous chromosomes in the question suggest the presence of genetic variation, which can affect the traits expressed in the Drosophila.