Different periods in human history are named for the materials used to make tools. dr. franklin is searching through layers of soil, looking for tools made by humans. after screening the top layer of soil, he uses a magnet to speed up the search.
which type of location is dr. franklin most likely searching?
a. a cave from before the stone age
b. a stone age cave a
c. bronze age battle site
d. an iron age farm

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.