True about polymorphism is: (PGI Dec 2006)
Ans: D (Single phenotype, single locus, - multiple allele] Polymorphisms is single phenotype, single locus & mu Itipie normal allele(r)Polymorphisms# Clinically ,'iarmless variationQ of DNA sequence# Normal variation in DNA sequence that have frequency of at least 1%. Usally, they don't result in a perceptible phenotype i.e,phenotype same'Q.They constitutes: Single base-pair substitution (often) & Deletions and insertionsThey don't alter protein coding sequence probaly due to degeneracy of genetic code although it is possible that it might alter mRNA stability, translation or aminoacid sequences.
Single locus - multiple normal alleles
Single locus - multiple abnormal alleles
Single phenotype: single Iocus->multiple normal alleles multiple abnormal alleles
Single phenotype: Single !ocus->>multiple abnormal alleles.
Immunology