Unlike a bar magnet<span>, however, </span>Earth's magnetic field<span> changes over time because it is generated by a geodynamo (in </span>Earth's<span> case, the motion of molten iron alloys in its outer core).</span>
This is an experiment where the researcher manipulates one variable, and control/randomizes the rest of the variables. It has a control group, the subjects have been randomly assigned between the groups, and the researcher only tests one effect at a time.
The large central vacuole would become dehydrated, because without enough water stored in it, there wouldn't be any turgor pressure (water pushing against the cell wall) to support the cell, which causes the plant to wilt.
Blood group b would exclude a male from being a father
