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

[BlueGas]

Is the Answer D?

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

So what's your method? Is it the same thing?

 

[obliviousninja]

Theres no need to use a ruler. Look at the provided answers, 3 of which are unreasonable

 

[BlueGas]

Theres no need to use a ruler. Look at the provided answers, 3 of which are unreasonable

Can you explain why the other 3 answers are unreasonable?

 

[Mr_Kap]

So what's your method? Is it the same thing?

Yeh. I didn't use a ruler though because you can see that the virus is just over double the scale they give you, and then I saw 13 in all the answers so I knew it must have been 130nm. And then you convert the nm to micro metres using their conversion.

 

[Chris_S]

Yeah I did the same as Mr Kap

 

[Flop21]

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/

I have no idea. But I know you will need a ruler + pencil for the exam due to possibly drawing diagrams and tables. It's my understanding that you are marked down for not having straight lines in tables, and labels for diagrams.

I've just always been taught to use pencil when drawing science diagrams.


Like others have said, for this particular question it's obvious that using their scale the image is a bit over 2 of their scales (2x50 + a bit = 130 looking at the possible answers). So that's 130nm, no answer for that there, so convert it to um (which is the usual unit of measurement for micro things), and you get D.

You can use a ruler to double check and clarify the length.

 

[Queenroot]

Can you explain why the other 3 answers are unreasonable?

I said this before. You can immediately cancel out anything in cm and the one that says 13nm because the scale for nanometres is right there and the virus is much larger. Then you use your deduction skills to eliminate the other two.

I think you are having trouble converting between all the units and should practice that.