Final answer:
The process of repeatedly crossing strains of an organism to consistently produce traits without variation is referred to as creating a 'pure line' or pure-breeding in classical genetics.
Step-by-step explanation:
When strains of a particular organism are repeatedly crossed to ensure that successive generations consistently exhibit certain traits without variation, this process is referred to as creating a 'pure line' or pure-breeding by scientists.
This is a concept rooted in classical genetics, where an organism that is homozygous for the trait(s) of interest is crossed with another homozygous organism, ensuring that the offspring also carry the trait. Over time, all offspring in such a lineage will express the trait in a uniform manner.
This technique forms the basis of Mendelian genetics, following the principles established by Gregor Mendel in the 19th century.
Moreover, this pure-breeding approach is distinct from modern genetic engineering techniques such as creating genetically modified organisms (GMOs), where specific genes are inserted, modified, or deleted to achieve desired traits.
Whereas GMOs are products of modern molecular biology, pure-breeding relies on traditional methods of selective breeding and natural inheritance.