If you have 100 grams of a radioactive isotope (the parent) with a half-life of 10 years, how much of the non-radioactive element (the daughter) will be left after 10 years?

List two modern organisms that have pentameral symmetry

List the advantages and disadavantages of the switch from persistent chlorinated hydrocarbon pesticides (such as ddt) to nonpersistent organophosphate pesicides. have the benefits of the switch outweighed the disadvantages? explain.

What are tissues? a groups of tissues that work together b basic units of structure and function c groups of cells that perform the same function d multiple organs that perform a major function