All of the Following Are True of Alleles,EXCEPT

Multiple Choice

All of the following are true of alleles,EXCEPT

A) they vary in nucleotide sequence.
B) when alleles of a gene differ,the organism is said to be homozygous.
C) for some diseases,if a person has only one disease allele,they may be healthy.
D) there may be many different alleles in the population.
E) pairs of alleles reside on homologous chromosomes.