Human late prophase karyotypes have about 2000 visible G bands. The human genome contains approximately 22,000 genes. Consider the region 5p1.5 through the end of the short arm of chromosome 5, which is identified on the late prophase chromosome in Figure 10.5, and assume the entire region is deleted. Approximately how many genes will be lost as a result of the deletion?

Key Concepts

Karyotype and G-banding

A karyotype is a visual representation of an individual's chromosomes, organized by size and shape. G-banding is a technique used to stain chromosomes, producing a pattern of light and dark bands that helps identify specific chromosomes and their structural features. In humans, there are about 2000 visible G bands, which correspond to regions of DNA that can be analyzed for genetic abnormalities.

Human Genome and Gene Count

The human genome is the complete set of genetic information for humans, consisting of approximately 22,000 genes. These genes are segments of DNA that encode instructions for building proteins, which perform various functions in the body. Understanding the distribution of genes across chromosomes is crucial for assessing the impact of genetic deletions or mutations.

Chromosomal Deletion

A chromosomal deletion is a type of genetic mutation where a segment of DNA is lost from a chromosome. This can lead to the loss of one or more genes, potentially resulting in various genetic disorders or phenotypic changes. In the context of the question, deleting the region 5p1.5 through the end of chromosome 5 would remove all genes located within that specific segment, affecting the overall gene count.