Question

Two allelic genes are located on

• A. The same chromosome
• B. Two homologous chromosomes
• C. Two non-homologous chromosomes
• D. Any two chromosomes

Answer 1

The correct option is B Two homologous chromosomes

Alleles are different forms of a gene. Example- Gene for an eye colour, i.e., gene for brown eyes, blue eyes, etc. Each cell contains two sets of each chromosome, one inherited from mother and another from father which are called as maternal and paternal chromosomes respectively. They are also called as 'homologous chromosomes'. They are similar but not identical, i.e., gene for eye colour is located at the same position in homologous chromosomes but maternal gene is different from paternal gene. Example- Maternal gene for eye colour is for blue eyes and paternal gene is for brown eyes but their location on chromosomes is the same.