Question

What are Alleles?

• A. two genes that occupy the different position on non-homologous chromosomes and that cover the same trait
• B. two genes that occupy the same position on homologous chromosomes and that cover the same trait
• C. two genes that occupy the same position on non-homologous chromosomes and that cover different trait
• D. two genes that occupy the same position on homologous chromosomes and that cover different trait

Hint:

• Gene A segment of DNA that codes for a functional product (e.g., a protein).
• Locus The specific physical location of a gene on a chromosome.
• Homologous Chromosomes Pairs of chromosomes (one from each parent) that have the same genes in the same order, but may have different alleles for those genes.
• Alleles Different versions of the same gene found at the same locus on homologous chromosomes. They code for the same trait (e.g., eye color) but can produce different phenotypes (e.g., blue eyes, brown eyes).

Answer 1

The Correct Option is B

In the context of genetics, alleles are defined as two or more versions of a gene that are found at the same place, or locus, on a chromosome. Specifically, alleles occupy the same position on homologous chromosomes and correspond to the same trait, although they can result in different outcomes of that trait. For example, if the gene is responsible for a flower's color, one allele may produce red flowers, while another may produce white flowers.

In this problem, we identify the correct statement describing alleles:

Option	Description	Analysis
1	Two genes that occupy the different position on non-homologous chromosomes and that cover the same trait	This option describes genes in different locations and is incorrect as alleles are on the same locus of homologous chromosomes.
2	Two genes that occupy the same position on homologous chromosomes and that cover the same trait	This option is correct as it accurately defines alleles.
3	Two genes that occupy the same position on non-homologous chromosomes and that cover different traits	This option is incorrect as it misunderstands the location relationship required by alleles.
4	Two genes that occupy the same position on homologous chromosomes and that cover different traits	This option is incorrect since alleles cover the same genetic trait although potentially resulting in different characteristics.

Thus, the correct explanation of alleles is: "Two genes that occupy the same position on homologous chromosomes and that cover the same trait."