Older fossils appear in rock layers– a. below new fossils.
b. above new fossils.
c. in the same layer as new fossils.
d. that also have new fossils.

What prevents odyssey from killing the sleeping cyclops

24. how are vaccines used to keep people healthy?

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.