What problem is caused by maps being two-dimensional

Could someone me with number one you

In which case would a scientist choose to use a dissecting microscope rather than a compound microscope

How does the molecular clock work? a. it analyzes the brain functionality of two different species.b. it examines and compares the physical characteristics of two different species.c. it illustrates relationships between two different species.d. it compares the number of mutations that exist in the dna of two different species.