Genes Located on the Same Chromosome
Two genes of two different traits located on the same chromosome are said to be:
- Linked — Correct Answer
- Alleles
- Independent
- Epistatic
Explanation:
Correct Answer: Linked
Genes located on the same chromosome are called linked genes. Because they are physically connected on the same DNA molecule, they tend to be inherited together, defying Mendel's Law of Independent Assortment. Linkage was discovered by T.H. Morgan.
Key Facts — Linkage
- Linkage is the exception to Mendel's Second Law (Law of Independent Assortment).
- The closer two genes are on a chromosome, the stronger the linkage (lower recombination frequency).
- Crossing over in the pachytene stage of Prophase I can break linkage and cause recombination.
- Linkage is a temporary/transient cause of genetic correlation (unlike pleiotropy, which is permanent).
Why Other Options Are Wrong
- Alleles: Alternative forms of the same gene at the same locus on homologous chromosomes — not genes for different traits.
- Independent: Genes on different chromosomes that assort independently — opposite of linked.
- Epistatic: Refers to intergenic interaction where one gene masks another — not about chromosomal location.
📚 About this Topic — Animal Genetics & Breeding
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
