Which part of the cells acts as a barrier to control what enters and leaves the cell?

Casts and mold are a type of preservation where the original material decays, leaving a mold in surrounding rock that can be filled with another sediment a. true b. false

Which spheres are involved when sedimentary rocks formed from parts of seashells at the bottom of the ocean? a.) biosphere, atmosphere, geosphereb.) geosphere, hydrosphere, biosphere c.) geosphere, exosphere, hydrosphered.) hydrosphere, biosphere, atmosphere

The process of meiosis produces only gametes, eggs or sperm. according to the diagram, how many sperm are formed from each cell that undergoes meiosis?