A-Level Biology - Measuring cells : Calibrate Eyepiece graticule, Magnification, Resolution 

Legit watching 2 days before P33 2024 and honestly can't thank you enough for precise, to the point and comprehensive explanation. Really grateful !!

During this pandemic and no lab classes... you are a life saver!!!! Thank you so much!

thankyou sooo much this has helped me understand eye piece graticule calibration so much better.

Thank you so much for all your videos!!!!! my AS are gonna start in around two months and we haven't started unit 3 in school yet so your videos are literally saving my entire bio unit 3 right now I honestly cant thank you enough you are such a life saviour I might start crying right now :''''''')

Fantastic!!! Thank you for your time and effort. It would be absolutely amazing if you could link us to word document that also has your explanation and example in written form so i can always look back to in my book.

I'm quite annoyed I have only just discovered your videos a day before paper 1, they're great!

extremely helpful! well explained and excellent example you gave for explanation ! thank you!

OMG I discovered your channel today and I watched all your videos. Thanks

This made my day! TY.

Thank you very much! you explain everything very clearly.

It's so awesome. Thank u for making it so easy to understand.

Thank you David. Very helpful.

Thank youu i didnt underatand it before but this video helped me understand the whole concept.

man you are a life saver !! thank you so much for the video 👌

Wow. Well explained. Thank you very much, sir!

These are sooo good and helpful. Wish I saw these earlier. I have a paper today

Oh i finally know how to calculate, thank God and thank YOU! Very clear explanation with working provided👍👍💯Also, the intro related to our daily life, what a good example to make me understand more~

This is excellent!! Keep up with the good work 💪👍

Its really wonderful Dr. David...thanks

This was great thank you!!

this is a life saver thank u!!

Youre so helpful, thank you thank you thank you

Mate this video banged. Cheers

Your videos are great THANK U

THANK YOU SO MUCH!!

hey David. great job excellent 👏

Great video thank you!

You.are.a.legend. Thank you.

You're amazing!

p3 exam tomorrow aaaa thank you for these videos, you're a lifesaver!!!

you’re a champ!

this helped so much thank you

thank you so much 🙌🏾

thank you soo much for making this video...

Thank u soooo much!!

thank you..really going to help for my exams

Great work

thanks for this great vid :)

Thank you so much 🥰

thank you sir

very useful for p5 A level (just in case) Thanks!

thanks

Hey David, how do you calculate percentage error

Hello! I have a doubt. For what dependent variables can you measure a mean? Can you list all potential dependent variables where we will have to repeat our experiment to calculate the mean? This is usually given as "Prepare a table for recording your data" as the first question. Thank you in advance!

so does the scale bar show image sizer actual size

Thank you so much. Your videos are always so helpful. :) One of the practical questions ask to count number of chloroplasts in the field of view. A sample shown under microscope that is divided into four sections, and I am supposed to count number of chloroplasts in a quarter. I am very confused about whether I should count the cells on the line (boundary) or not, should I count the cells on the line? Or should I ignore the cells on the line and only count the cell inside the quarter?

what magnification did u use to calibrate ?

Hey thanks great vid, also cant you do stage micrometer division divide by equivalent eyepiece graticule units? So 0.1÷40 =0.0025mm Gives same value.

How is the smallest division in stage micrometer 0.1mm?

Hey David , I have a question. If it asked for the actual size of the specimen after you calibrate they eyepiece graticule would you first a line the specimen and work out it's length in e.u and then divide it by the magnification ? Great video btw .

YASSSSSSSSS THANKYOUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU

can i know how much is the magnification of 25um of EG?

calculate the calibration factor for the eyepiece graticule at x40(x4 objective lens) how can I solve this question , thank youu

Hi ! Great video ! I have a question. I am a private candidate, so I can't fully visualise what is happening here, so please help me understand. What does the scale bar represent ? If we can use it to get the image size already then why are we measuring the size of the image again ? That part was a bit confusing for me. Like what did 20000 and 20 represent to give us the magnification?

I like it

can you please make videos for A level chemistry please

Why is it not possible to see a cell and the stage micrometer scale at the same time?

2024. Still useful!

I love your handsome smile no homo ;v

In 1:44 there is a typo "the the"

We learnt magnification = actual ÷ image

Thanks for the awesome video, why is your passport in your shoe?

you are so funny

groso!