What happens when both ends of a chromosome undergo deletion to form a ring chromosome?

The formation of a ring chromosome typically occurs when both ends of a linear chromosome break off and the two ends reconnect, forming a circular structure. This type of chromosomal alteration can lead to the loss of genetic material at the sites of the deletions. As a result, the symptoms and effects on phenotype arise primarily from this loss of genetic content.

The answer points to the fact that deletions can remove essential genes or regulatory elements that are crucial for proper development and function. The specific impact on an individual's phenotype will depend on which genes are lost during the deletion process. In many cases, such deletions can lead to a variety of symptoms, which may include developmental delays, growth issues, or other health-related problems as a consequence of the missing genetic instructions.

While it is true that some genetic alterations can be benign, ring chromosomes often carry a risk of significant phenotypic consequences due to the deletions involved. Thus, the correct answer correctly highlights that symptoms typically arise from the genetic material that is lost during the ring formation process.