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Biology Help

I need help with this question because i got 192 micrometers but the answer is 200
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Avatar for Official-21
Official-21
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Reply 2
Avatar for biwltyad
biwltyad
4
The way I find it easier to solve this kind of question is by using, if I know the right name, proportions.
Let's name the first cell, the bacterial one B (because it starts with B) and the plant one P.
I will write magnification of B as mB and magnification of P as mP. This is completely unnecessary but it is quicker than writing the whole thing each time.
lB will be the length of B and lP the length of P.

As it writes on the diagram:
mB=50000
mP=500
lB=2
lP= x

Because as you magnify the cell, it appears larger (you increase the magnification, the length will decrease) we will inverse the proportions so mP/mB=lB/lP ==> 500/50000=2/x ==> 50000/500=x/2 ==> x/2=100 ==> x= 2*100= 200

You can do it much less complicated than I did but I tried to explain everything and I would a very bad teacher :smile:))

What did you do that you got 192? It is easier to learn to do it correctly by understanding why it is wrong the way you've done it, this is why I am asking :smile:))

I hope it helped and that I explained in a way that is understandable :smile:))
Reply 3
Avatar for jaisuf
jaisuf
13
Magnification goes from 50000 to 500, that's 100 times less magnified.

It is implying the measured distance on the paper is equal, therefore knowing the distance on the left equates to 2 micrometres, you simply have to multiply 2 by the factor by which magnification decreases on the right.

2 x 100 = 200
Original post by Official-21
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Original post by Official-21
I need help with this question because i got 192 micrometers but the answer is 200




Remember the equation - actual size x magnification = image size
You're told that both cells have the same image size but different actual size and magnification
1. calculate image size for the bacterial cell - 2 x 50000 = 100000
2. calculate actual size of the plant cell - 10000/500 = 200 micrometers

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