Measuring the size of red/white blood cells (2 Viewers)

[BlueGas]

I have trouble measuring the size of red/white blood cells, how do I measure their size?

 

[Flop21]

Don't questions like this give you a scale? So the main the we should be learning is really just calculating the size from a scale, and knowing the units of measurement?

 

[BlueGas]

Don't questions like this give you a scale? So the main the we should be learning is really just calculating the size from a scale, and knowing the units of measurement?

I don't know at all how to measure, for example how would you do questions like these?

 

[Flop21]

1mm = 1000µm (micrometre)

From this thread, here is the method:

To measure a rbc first you must set up the light microscope appropriately. The magnification really doesn't matter so long as you manage to spot the cells, but I would recommend using a X40 magnification. Once you can see the cells you use grid paper or a ruler to measure the field of view or the circle of light produced by the microscope on the sample. Once you have the field of view diameter in millimetres, multiply the length by 1000 to get the length in micrometres. Next you divide this length by the magnification as you are zooming in and reducing the diameter. After this you estimate how many cells would fit along the diameter, you then divide the length of the diameter by the amount of cells.

Working out.
The length of the field of view was 2mm
2x1000=2000micrometers
2000/40=500
I estimated that there were around 70 cells
500/70=7.14 micrometres

http://community.boredofstudies.org...986/measuring-size-red-white-blood-cells.html


Here is another link with a method (HSC Online):

http://www.hsc.csu.edu.au/biology/core/balance/9_2_2/922net.html#net3


Hopefully that helps, but tbh this is something I need to study as well.

EDIT: Also you need a ruler for these questions.

 

[BlueGas]

Quick bump, for the 2nd photo, how would I measure the diameter?

 

[BOS Secret Service]

measure with ruler. Record in cm. Divide answer by 500 (as it says the paper image is x500 magnified). Convert to appropriate unit of measurement

 

[BlueGas]

measure with ruler. Record in cm. Divide answer by 500 (as it says the paper image is x500 magnified). Convert to appropriate unit of measurement

So I measure the white blood cell indicated by X?

 

[Queenroot]

Just know that an RBC is usually 8 microns wide and most WBCs are larger than that

 

[Queenroot]

Also you can eliminate anything that is in millimetres because cells are microscopic

 

[BlueGas]

Just know that an RBC is usually 8 microns wide and most WBCs are larger than that

Okay so I just came across a HSC question asking to 'draw a scaled diagram' of a red blood cell, if I know that RBC are usually 8 microns, how much cm would that be if I was to draw a scaled diagram?

 

[rand_althor]

Okay so I just came across a HSC question asking to 'draw a scaled diagram' of a red blood cell, if I know that RBC are usually 8 microns, how much cm would that be if I was to draw a scaled diagram?

Depends what your scale is. You could do 1cm:2microns.

 

[BlueGas]

Depends what your scale is. You could do 1cm:2microns.

And just so I know the terms, microns is micrometeres and micrometes is "µm" right?

 

[rand_althor]

And just so I know the terms, microns is micrometeres and micrometes is "µm" right?

Yes.

 

[Stimuli]

In regards to drawing scaled diagrams of RBC's, what range can you draw their size in? I've been taught that their size is 5-7µm, so would it be acceptable to draw a RBC with a diameter within that range?

 

[BlueGas]

Quick bump, how would I do this question?

 

[Mr_Kap]

Quick bump, how would I do this question?

Is the Answer D?

I want to get it right before i explain a wrong method. lol

 

[BlueGas]

Is the Answer D?

I want to get it right before i explain a wrong method. lol

Yep the answer is D.

 

[Flop21]

You just have to use the scale, then use your ruler, so you get 130, then convert the units into micrometres, and it already gives you "1um = 1000nm"

So we have 130nm, converting that (divide by one thousand > scale), you get 0.130um.

 

[BlueGas]

Do you mean measuring the width of the virus with a ruler?

 

[BlueGas]

Howcome there's no ruler mentioned in the board of studies link under Biology? If I need a ruler for these sort of questions, why isn't there a ruler mentioned under Biology?

https://studentsonline.bos.nsw.edu.au/go/exams/Exam_equipment/