How can teeth be helpful in determining age of a deceased body?

Where can dna be found in a prokaryotic cell

10. in which phase will crossing-over occur? a. mitosis b. metaphase ii c. prophase i d. meiosis ii

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?