Answer:
D. Only B and C are correct.
Step-by-step explanation:
An allele is an alternative form of a gene that can occur at a specific location on a chromosome. Alleles can be either dominant or recessive, meaning that they can express themselves in the phenotype (observable characteristics) of an organism either over or under the influence of another allele for the same gene. Alleles can also represent alternative forms of a gene, with each allele encoding a slightly different version of the protein or enzyme that the gene codes for.
All of these statements are true for alleles. However, the option "They can be identical or different for any given gene in a somatic cell" is not true. Alleles are present in pairs in a somatic cell, with one copy inherited from each parent. These two alleles may be identical or different, depending on the gene in question.
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