This is called a monohybrid experiment. A test cross is performed between two plants that breed true for one trait, and the resulting trait for each offspring plant is determined The first, true-breeding generation, is called the parent, P generation.
Lumbar Degenerative Disc Disease Video. The natural history of lumbar degenerative disc disease is relatively benign. The pain tends to be intermittent, and although at times the pain may seem to be getting worse, the painful symptoms are generally not progressive. While the disc degeneration will progress, the low back pain and other symptoms do not tend to get worse with the progression of the degeneration.
Degenerative disc disease and sciatica facts. 1  The discs of the spine serve as cushions between each vertebral segment. 2  The discs are designed somewhat like a jelly donut. 3  Degeneration (deterioration) of the disc makes the disc more susceptible to herniation (rupture), which can lead to localized or radiating pain. Sciatica can result from disc herniation (ruptured disc) when nerves in the low back are irritated.