Only those proteins synthesized during the brief pulse phase are radioactively tagged. these tagged proteins can be tracked through the chase period to determine their location in the cell. the data below were obtained from a pulse-chase experiment in which cells were examined at different times during the chase period. the numbers represent the radioactivity (measured in counts per minute) recorded at each of the indicated sites. the higher the number, the greater the radioactivity.

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.