Which metal ion is a cofactor for the enzyme dna polymerase during dna synthesis?

What is thought to have caused the mass extinction at the end of the cretaceous period?

If a baby girl guinea pig looks almost identical to its mother, does this then mean that it inherited more alleles from its mother? explain. (hint: think about the vocabulary words dominant and recessive.)

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.