Quick Lesson Recap Sheet Lesson 1 (Classification of Living Things) Week 2 Q. Fill in the following blanks. a) Scientists classify living things based on _____________ that living things share. b) ________________ is an example of Physical characteristics. c) ________________ is an example of Chemical characteristics. d) Scientists study genetic material such as __________ and _________. e) _____________ and _____________ can also show if organisms are related.