Brownsville is a borough in Fayette County, Pennsylvania, United States, officially founded in 1785 located 35 miles (56 km) south of Pittsburgh along the Monongahela River.
2nd Item Specification: Given a group of organisms and a key, classify organisms based on observable characteristics. Depth of Knowledge Level 1. 1  A tool used by scientists to identify unknown organisms based on observable characteristics is called a. 2  dichotomous key.
Scientific tools for making observations include a microscope, which is a tool used to see very small objects. In your science lab you use a compound microscope to see cells in 2-D, but a scientist can use a scanning electron microscope to view tiny objects in 3-D.