A pair of homologous chromosomes in Drosophila has the following content (single letters represent genes): Chromosome 1 RNMDHBGKWU Chromosome 2 RNMDHBDHBGKWU How does the pairing diagrammed in part (b) differ from the pairing of chromosomes in an inversion heterozygote?

Key Concepts

Homologous Chromosomes

Homologous chromosomes are pairs of chromosomes in a diploid organism that have the same genes at the same loci but may carry different alleles. In Drosophila, as in other organisms, these pairs are crucial for processes like meiosis, where they align and exchange genetic material. Understanding their structure and function is essential for analyzing genetic variations and inheritance patterns.

Inversion Heterozygote

An inversion heterozygote is an individual that has one chromosome with a segment inverted compared to its homologous chromosome. This structural rearrangement can affect gene expression and recombination during meiosis, leading to unique pairing configurations. Recognizing how inversions influence chromosome behavior is vital for understanding genetic diversity and evolutionary processes.

Chromosome Pairing and Recombination

Chromosome pairing and recombination are critical processes during meiosis where homologous chromosomes align and exchange genetic material. This pairing is influenced by the structural integrity of the chromosomes, including any inversions. Analyzing how these processes differ in normal versus inversion heterozygotes helps elucidate the mechanisms of genetic variation and the potential for producing viable gametes.