How many significant digits are in 4,050? -1 -2 -3 -4

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

Idon’t know the answer and i’ve been stuck on it for a while now skskskskks

Color blindness is a recessive trait. the gene for color blindness is on the x chromosome. the family tree below shows the traits of color blindness. the only unknown is the father in the generation.