Question

Your biology teacher asks you to do the impossible, you must measure the diameter of one algae cell. You are about to turn in a blank lab report when you friend comes and says it's an easy task. At 40x your field of view is .50mm or 500um, If you look carefully you can see 15 algae cells spanning the field of view. The diameter of one algae cell is approximately
 A) 0.03um
 B) 1.50 um
 C)3.00um
  D)33.3um

Answer 1

Answer: D) $33.3\mu\text{m}$

Explanation:

If we assume the shape of algae cell is round or sphere.

Given: The total number of algae cells spanning the field of view = 15

At 40x field of view is $0.50\text{ mm or }500\mu\text{m}$

To calculate the diameter of one algae we need to divide $500\mu\text{m}$ by the total number algae calls spanning the field , we get

The diameter of one algae cell :

$\dfrac{500\mu\text{m}}{15}=33.33333333\mu\text{m}\approx33.3\mu\text{m}$

Hence, the diameter of one algae cell $\approx33.3\mu\text{m}$

Answer 2

Answer:

Option D

Explanation:

The field of view is 0.50 mm or 500um.

Thus, if this span of view has 15 algae cells then these algae cells are arranged in linear order adjacent to each other.

Hence the sum of diameter of all fifteen algaes is equal to 500um

Now , the actual size of view

$= 500$ um

sum of diameter of 15 algae $= 500$um

Diameter of one algae cell is equal to $\frac{500}{15} \\= 33.33$um

Hence, option D is correct