What is a limitation of using pedigrees for positional cloning?

Ineed the definitions of all of these words nasap i will give 1o points to whoever awnsers

Plz fast biotechnology is a growing field of applied biology. many crops such as corn have been engineered to be resistant to herbicides. therefore farmers can spray these chemicals to kill weeds growing near the crop without worries of killing the crop itself how does this type of biotechnology work? a. by changing the genetic make up of the crops. b. by causing the crops to kill the weeds. c. by changing the type of crops used. d. by changing the location of the crops.

Which of the following is an eon in the time scale? phanerozoic proterozoic archean all of the above