Multiple alleles are present
- on different chromosomes
- at the same locus of the chromosome
- at different loci on the same chromosome.
- on non-sister chromatids
Answer
(2) at the same locus of the chromosome
Solution
Multiple alleles are more than two alternative forms of the same gene (e.g. IA, IB, i of ABO blood groups).
∵ All alleles of a gene occupy the same locus (position) on homologous chromosomes ⇒ multiple alleles are present at the same locus of the chromosome (an individual carries only two of them).
Answer: (2)