As part of a lab exam, you are given a vial of orange crystals. when you add them to pure, neutral ph water, the ph changes to 13. other tests show that the crystals consist of as single chemical, which you could conclude is
a. a weak acid.
b. a weak base.
c. neutral.
d. a strong acid.
e. a strong base.

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.