Biology-Online • View topic - please help me - a level

Join for Free!
122503 members

please help me - a level

Discussion of all aspects of cellular structure, physiology and communication.

Moderator: BioTeam

please help me - a level

Postby red.ninja13 » Wed Oct 24, 2007 9:51 pm

im doing a learn at home a level in biology (aqa spec b), and theres one part i cant make any sense of, no matter where i look on the net, and as i am doing it learn at home i have no access to microscopes or anything.

i dont understand how to do calculations when looking at stuff through a graticule and stage micrometer, can anyone explain it to me, or give me anywhere with examples i can try and work out myself?

thank you
Posts: 10
Joined: Wed Oct 24, 2007 9:17 pm

Postby blcr11 » Thu Oct 25, 2007 1:59 pm

For measuring the size of things—making use of the scale and reticule: ... uring.html ... ntlab.html

For counting cells with a graticule: ... nting.html

Alternatively, for cell counting, search for “hemocytometer” or "haemocytometer" and/or try and find an instruction pamphlet from one of the manufacturer’s websites.
Posts: 672
Joined: Fri Mar 30, 2007 4:23 am

Postby red.ninja13 » Thu Oct 25, 2007 11:16 pm

lets see if i'v got this correct........

1mm = 1000µm

1 stage unit = 0.01mm
3 graticule units = 1 stage unit

3g = 10µm
1g = 10∕3
1g = 3.33µm

3g = 0.01mm
1g = 0.01∕3
1g = 0.0033mm

so could i use the equation

ng = ns
1g = n/n

then times by 100 to get µm

have i got it? :shock:
Posts: 10
Joined: Wed Oct 24, 2007 9:17 pm

Return to Cell Biology

Who is online

Users browsing this forum: No registered users and 2 guests