Explain how the number of chromosomes per cell is cut in half during meiosis in which the diploid parent cell produces haploid daughter cells.

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.

Which class of molecules functions as chemical signals? hormones water carbohydrates proteins