In genetics, linkages refer to the linking of genes of the

Step 1: Analyze the question The question asks what "linkage" means in genetics, specifically which genes are involved in the linking.

Step 2: Explain the concept Genes are located on chromosomes. When two or more genes sit on the same chromosome, they are physically connected and tend to be inherited together during gamete formation. This is called linkage.

• Genes on different chromosomes assort independently, as in Mendel's law of independent assortment.
• Linked genes do not assort independently, because they travel together on the same chromosome.
• Linkage can be broken by crossing over during meiosis (prophase I), and the closer two genes are, the less likely they are to be separated.

Step 3: Evaluate the options

• A. Same chromosomes: Correct. Linked genes lie on the same chromosome.
• B. Different chromosomes: Incorrect. These genes assort independently.
• C. Same nucleus: Too general. All the genes of a cell are in one nucleus, but that does not make them linked.
• D. Different nuclei: Incorrect and not relevant to linkage.

Step 4: Answer Linkage refers to the linking of genes on the same chromosome.

Exam tip: Remember "Linkage = Located on the same chromosome". If a question mentions genes on different chromosomes, think independent assortment instead.