Can some on please help me with this assignment

Florian discovers a rock that is broken into pieces. each piece has several bands. which type of rock does florian predict these pieces will change into when subjected to heat and pressure? igneous magma metamorphic sedimentary

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

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.