To assess the accuracy of statements regarding genes, each is examined individually:
- (A) Genes are located on chromosomes: This statement is accurate. Genes, which are segments of DNA, reside on chromosomes, the structural units within the cell nucleus.
- (B) Split genes are composed of exons only: This statement is inaccurate. Split genes, also known as interrupted genes, comprise both exons (coding regions) and introns (non-coding regions that are subsequently removed during RNA splicing).
- (C) Genes move from one linkage group to another: This statement is generally inaccurate. Genes are grouped based on their chromosomal location and typically do not shift between linkage groups unless rare events like translocation or certain types of genetic recombination occur.
- (D) Chromosomes with identical arms on which genes are located are known as isochromosomes: This statement is accurate. Isochromosomes possess identical arms, a result of misdivision at the centromere leading to the duplication of one arm.
Based on this analysis, statements (A) and (D) are correct, while statement (B) is incorrect due to its definition of split genes. Consequently, no single option perfectly reflects complete accuracy, and potential misinterpretations in the provided choices may exist. However, if adhering to the established structure, the option referencing (A), (B), and (D) highlights factual inaccuracies while maintaining a check on the question's options. Careful consideration of the context is advised.