A researcher investigates an organism found on the ocean floor. The organism is asymmetrical. It lacks a body cavity, body tissues, organs, and a nervous system. The researcher finds that the organism can fully regenerate itself if parts of its body are broken off. Into which phylum should the researcher classify the organism?

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.