What are alleles a. the decoders of the dna message b. two forms of single genes c. the basic unit of inheritance d. a measurable factor.

B describes what an allele is correctly. An allele is a variation of a gene, like said by the second option.

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the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.