Chest Radiology > Pathology > Atelectasis > General. Atelectasis is collapse or incomplete expansion of the lung or part of the lung. This is one of the most common findings on a chest x-ray. It is most often caused by an endobronchial lesion, such as mucus plug or tumor.
A Labradoodle, a crossbreed between a poodle and a retriever. A crossbreed or crossbred usually refers to an organism with purebred parents of two different breeds, varieties, or populations.
backcross. in experimental genetics, union between a heterozygote of the first generation and one of its parents or an organism genetically identical to one of its parents. double backcross the mating between a double heterozygote and a homozygote.n experimental genetics, union between a heterozygote of the first generation and one of its parents or an organism genetically identical to one of its parents. double backcross the mating between a double heterozygote and a homozygote.