Question

A human rbc is approximately 8 µm in diameter. an unknown bacterium measures 1 ocular space using the oil immersion objective compared to 2 minor spaces on the stage micrometer.

a.how big is the unknown bacterium (report in micrometers) and
b.how does its size compare to the rbc (how many times bigger is one versus the other)? (4pts)

Answer 1

a)
size = (number of minor spaces x 10μm) / number of ocular spaces
= (2 x 10) / 1
= 20μm

b)Since the RBC has a size of 8μm and the bacterium 20μm, the bacteria is bigger. The Bacterium is bigger than the RBC by 20μm / 8μm
Hence the bacterium is 2.5 times bigger than the RBC.