Question

mendel was able to study seven traits in all the pea plants in each generation. which of his hypotheses allowed him to analyze each trait separately?
if two different alleles for a gene occur together, one of the alleles may be expressed while the other is hidden
when gametes are formed, each gamete carries only one allele for the gene.
there are alternate versions of a alleles called genes.
for each inherited trait, there is only one copy of the gene that codes for that trait.

Explanation:

Mendel's law of segregation (when gametes are formed, each gamete carries only one allele for the gene) allows for the analysis of each trait separately. This is because it ensures that alleles for different traits assort independently during gamete formation, enabling the study of individual traits without interference from other alleles. The other options either describe aspects of gene expression (dominance - "If two different alleles..."), misstate the concept (genes are not alternate versions of alleles; alleles are alternate versions of genes), or are incorrect (for each inherited trait, diploid organisms have two copies of the gene, not one).

Answer:

When gametes are formed, each gamete carries only one allele for the gene.