Speciation occurs when: A. two populations become geographically isolated
B. enough differences accumulate between two populations that they can no longer interbreed
C. gene mutations accumulate
D. all of the above

Located at the epidermal-dermal junction of the skin. select all true statements about the transformation of melanocytes into abnormal cell

Modern computers can store about as much information as the human brain. true false its false i took the test

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.