Problems in using common names to universally identify living things include:

names mean different things to different people.

foreign names may not be understood.

many names may exist for the same organism.

there may be no common name for an organism.

common names lack sufficient precision.

enough common names are not available to name every living thing.

multiple choice.

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.