Gene Forms Explained

Genes are specific sequences of DNA that contain instructions for building proteins or performing functions within an organism. These instructions determine various traits.

A single gene can exist in multiple variations or forms within a population. Each of these distinct forms of the same gene is called an allele.

For example, the gene responsible for pea flower color can have an allele for purple color and an allele for white color.

Analyzing the Options

• Alleles: This is the correct term for the different forms or variations of a single gene.
• Chromosomes: These are structures within cells that contain the genetic material (DNA). Genes are located on chromosomes, but chromosomes themselves are not different forms of a gene.
• Genotypes: This refers to the specific combination of alleles an individual possesses for a particular gene or genes (e.g., PP, Pp, or pp for flower color). It's the genetic makeup, not the gene forms themselves.
• Phenotypes: This is the observable physical or biochemical characteristic of an organism, resulting from its genotype and environmental influences (e.g., purple flowers or white flowers). It's the expression of the alleles, not the alleles themselves.

Therefore, the different forms of a gene are called alleles.