1. which structures are common to both cells

me see vision many moons ago we weak me find water braves drink we strong men find us we shoot they gone we strong know spirit brother

me show vision too you look up at stars tonight see how your story goes out it tell how life for you go be strong little stone

you fly high see my people see finer in life see horse go down hill meet you bring you home little stone

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .