from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A cross between an individual exhibiting the dominant phenotype of a trait and an individual that is homozygous recessive for that trait in order to determine the genotype of the dominant individual.
- transitive verb To subject to a testcross.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from that of the offspring
Sorry, no etymologies found.
If the mystery mutant and the known mutant sit on different chromosomes or a long way from each other on the same chromosome the grandkids of your ‘testcross’ will have an even mix of either one of the mutations, both or neither.