Watch this video to find out how to prepare an onion root tip squash. Listen to the mistakes that students make and for handy tips of what to include in your lab book.
Hi! I'm doing this practical this Wednesday and I'd like to ask where I could find the method you're using in this video please? I've been asked to research a method and I really like yours. I'd be really happy if you could reply! Thank you 😁
hi, yes the acid is added to break the hydrogen bonds that join the bases holding the two strands of DNA together. Heating the acid increases the rate of reaction. We want to break the bond between some of the bases so that the stain can bind with the bases and thus highlight the chromosomes against the rest of the cell. hope that makes sense??
hi sorry for the delay, you also asked something about the cell wall. The acid isn't for breaking down the cell wall as remember that just allows substances to move freely through it as it basically has large pores or gaps that allow most substances to pass through. We also want to hold the cell together and not cause it to break down so we can count our cells to work out the mitotic index.
Her toe Fell off its just a standard piece of lab equipment used so you don’t have to touch the cover slip (as that would leave fingerprints) and you lower it down flat from an angle so you don’t get trapped air bubbles underneath - good luck.
Lots of questions and no answers
This is honestly so helpful thank you miss
Has anyone ever told you that you look like nessa from gavin and Stacey. Love the vid by the way :)
Tq mam useful vedio and more vedio sent please
Hi! I'm doing this practical this Wednesday and I'd like to ask where I could find the method you're using in this video please? I've been asked to research a method and I really like yours. I'd be really happy if you could reply! Thank you 😁
Excellent video. I've wanted to do this myself for a long time.
Is it safe to heat a 1M solution of hydrochloric acid?
Great video but can you please explain why acid is added and why it is put in a water bath for 4 mins?
hi, yes the acid is added to break the hydrogen bonds that join the bases holding the two strands of DNA together. Heating the acid increases the rate of reaction. We want to break the bond between some of the bases so that the stain can bind with the bases and thus highlight the chromosomes against the rest of the cell. hope that makes sense??
@@vanessachristian696 Thank you but does the HCl not also hydrolyse the cell wall, allowing the stain to permeate and bind with the bases?
hi sorry for the delay, you also asked something about the cell wall. The acid isn't for breaking down the cell wall as remember that just allows substances to move freely through it as it basically has large pores or gaps that allow most substances to pass through. We also want to hold the cell together and not cause it to break down so we can count our cells to work out the mitotic index.
@@vanessachristian696 Thank you very much for your answers :)
why are we rinsing the root with water
If we allow the acid any longer you will have a pickled root instead of cells at various mitotic stages.
Hi, why do you rinse the root tip with cold, distilled water? Thank you!
To remove the acid and to stop the process. The stages of Mitosis will be frozen in time.
Why do we need a mounted needle? Please answer quickly as I have this practical tomorrow! X
Her toe Fell off its just a standard piece of lab equipment used so you don’t have to touch the cover slip (as that would leave fingerprints) and you lower it down flat from an angle so you don’t get trapped air bubbles underneath - good luck.
Vanessa Christian thank you so much! Thankfully the practical has been switched to Wednesday x
Could also be for piercing the root as to spread the thin cells around?
Why did u use 1M hcl?
Safer than 5ml and does same job if you then heat it
5M
Vanessa Christian thanks for the reply! Your videos are very useful ❤️