Water-siphon test. Dr Henry Knipe â and Dr Marcin Czarniecki â et al. The water siphon test may be performed as part of a barium swallow to assess for gastro-oesophageal reflux in a hiatal hernia. It is performed in the supine RPO position with the patient drinking water continuously. The test is said to be positive if there is visible barium reflux in the oesophagus.
In some instances, offspring can demonstrate a phenotype that is outside the range defined by both parents. In particular, the phenomenon known as overdominance occurs when a heterozygote has a more extreme phenotype than that of either of its parents. Indeed, in a few examples, a trait that shows overdominance sometimes confers a survival advantage in the heterozygote (Parsons & Bodmer, 1961).
Sometimes the copy from mother or father is silenced, and only the copy from one parent is active. If the only active gene is damaged, it can show up in the form of genetic disease. An example of genomic imprinting, is the mixing of tigers and lions.Who the mother is, has direct effect on the offspring. A mother tiger and a father lion, results in a liger. Ligers are much bigger than either parent. A mother lion and a father tiger, results in a tigon.ometimes the copy from mother or father is silenced, and only the copy from one parent is active. If the only active gene is damaged, it can show up in the form of genetic disease. An example of genomic imprinting, is the mixing of tigers and lions.