How does an allele cause a trait in an organism?

Alleles cause the production of a certain type of protein.

Explanation:

Genes mutate and can get two or more different or opposite forms, every form of such gene is known as an allele.

An allele is one of the common causes for deciding the trait or character of an individual because it causes the production of a certain type of protein.

Thus, the correct answer would be Alleles cause the production of a certain type of protein.

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