Multiple cell types, including neurons and glia, can arise from the same precursor cells. because of this potential to give rise to many different types of tissue, these precursorcells are also called which of the following? choose the correct option. a) neuroblasts
b) newly generated neurons
c) daughter cells
d) neural stem cells

Which quantities are scalars? choose all that apply a.distance b.speed c. acceleration d.velocity

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?