USC researchers track down the stem cells that create feathers
...its unique functional morphology. For example, the radially symmetric downy feathers found on chicks and on th...ated: the stem cell ring is horizontally placed in radially symmetric downy feathers, but is tilted in bilaterally symmetric feathers, with the lower end of the...Neurons find their place in the developing nervous system with the help of a sticky molecule
...of cells. From that zone, crawling neurons migrate radially out toward the surface or "superficial" part of the developing cortex, giving rise to a laminar structure. Neurons forming layers 2 and 3, the focus of the current study, are born last and so must elbow their way through cells lying in earlier formed...How did bilaterally symmetric flowers evolve from radially symmetric ones?
How did bilaterally symmetric flowers evolve from radially symmetric ones? To address this important question... surviving to the juvenile stage, than plants with radially symmetric flowers. "This study reveals that natural selection can play a key role in the evolutio...