Pure-bred plants have two copies of the _________________________ gene for each trait
To determine the missing term, we need to understand the concept of inheritance in plants. Each plant inherits two copies of each gene, one from each parent. These copies are known as alleles. Alleles can be either the same (homozygous) or different (heterozygous) for a particular trait.
Based on this information, the missing term in the statement is "allele." Pure-bred plants have two copies of the same allele for each trait. This means that both alleles are identical and homozygous for that particular trait. Having two identical alleles allows the expression of specific traits consistently in subsequent generations of pure-bred plants.