What do you know about an organism's parents if it is heterozygous for a certain trait?
a. both parents supplied the same allele.
b. the parents supplied different alleles.
c. the parents had different traits.
d. the parents had the same traits.

Option B, The parents supplied different alleles

Explanation:

The genotype of any offspring is decided by the equal contribution of allele from both the parents. Hence, even when an organism is heterogyzous it is clear that the  allele pair expressing the trait (due to the heterozygous pair) is formed by the contribution of both the parents equally which means one allele is given by one parent while other allele is given by other parent.

For instance -

For any heterozygous allele pair let’s say “Xx” , allele “X” would be donated by one parent while allele “x” would be donated by another parents.

Hence in order to form a heterozygous offspring the two parents need to contribute different alleles.

Therefore, option B is the correct answer

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