Schwann cells are the neuroglia that produces myelin sheaths. There is a formation of multiple layers of the glial plasma membrane around axons. The cytoplasm and nucleus of Schwann cells from the outermost layer while the inner part has multiple layers of the Schwann cell membrane. The outer nucleated cytoplasmic layer of the Schwann cell that encloses the myelin sheath is called neurolemma. It is found only around axons in the PNS. Its function is to serve in the regeneration of injured axons by the formation of a regeneration tube.
In this, the controlled variables are stirring and type of sugar. As more stirring might elevate the amount of sugar that dissolves, and different kind of sugars might dissolve in distinct concentrations. So, in order to make sure a fair test, there is a need to keep these variables similar for each cup of water.
it's not A because there's no such thing as favorable traits whenever it comes to incesticide and for B the majority of Beatles and future generations will also die that's only to the ones that died but that can not happen, which means that D is the one that will be the correct answer because if one lives, then the rest of the generations live due to immunity in the generation that started it.