Question

generalize: if either allele is the dropdown allele for a trait, the organism will exhibit that trait. an organism will express the recessive trait only when dropdown recessive

Explanation:

Analyze the first blank

The sentence states: "If either allele is the [blank] allele for a trait, the organism will exhibit that trait."
In genetics, if an organism has at least one dominant allele, it will express the dominant phenotype. Therefore, the first blank must be "dominant".

Analyze the second blank

The sentence states: "An organism will express the recessive trait only when [blank] recessive."
A recessive trait is only expressed phenotypically when the organism carries two copies of the recessive allele (homozygous recessive). Thus, the organism must have both alleles as recessive. The appropriate phrase for the dropdown is "both alleles are".

Answer:

Generalize: If either allele is the <blank>dominant</blank> allele for a trait, the organism will exhibit that trait. An organism will express the recessive trait only when <blank>both alleles are</blank> recessive.