Vinegar has a ph of 3, and household ammonia has a ph of 11. is the concentration of h+ greatest in the vinegar or ammonia?

The bacteria found in soil is usually harmful and measures are taken to remove any traces of microorganisms. true or false

Are the layers of rock above and below the coal older or younger?

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.