What is sex linkage primarily dependent on?

• A. Type of cell in the organism
• B. Environment factors only
• C. Gender of the individual
• D. Chromosomal structure

Answer: (D)

Sex linkage comes from where a gene sits on the chromosomes. If a gene is located on the sex chromosomes, its inheritance follows the pattern of those chromosomes, which differs between males and females (for example, XY males and XX females). This chromosomal location, not the type of cell, environment, or the person’s gender, determines how the trait is passed on and expressed. The different patterns you see—such as why certain traits appear more in one sex or how carriers work—all arise from the chromosomal structure carrying the gene.