OFFICIAL OCR A Biology A level Exam Thread- 12th, 20th and 26th JUNE 2017Watch
Biological Processes (Modules-1,2,3,5)- June 12th
Biological Diversity (Modules-1,2,4,6)- June 20th
Unified Biology (Modules-1,2,3,4,5,6)- June 26th
I hope you have all been revising hard, Don't forget the AS topics!!
I made a huge booklet (over 130 pages) of all the topics using the points on the spec for everything I need to know, but it is too big to upload. I have broken it up into smaller parts too but it is still too big
Does anyone have a step-by-step process for how to do a serial dilution?
1. Using a pipette, extract 10cm3 of solution into a test tube.
2. Then take 1cm3 from the the test tube and add 9cm3 water.
3. (using bung) Invert and shake several times, and then extract 1cm3 of solution and add to another test tube.
4. add 9cm3 water and repeat process 3 and 4 until desired amount is obtained.
I think the Heart is definitely gonna come up it wasn't really in any of the AS papers last year and this year. The only thing that came up on it was an MCQ in the Breadth paper last year
Is it cohesion, adhesion and tension? the adhesion and cohesion work together to exhibit capillary action
its a)transpiration pull continuous column of water (cohesion &adhesion)
b) root pressure with the osmosis of water after the medulla is concentrated with minerals with the introduction of the casparian strip.
c) capillary action
well thats what the book says atleast (ocr a bio p217)
correct me if im wrong
Ornithine is converted into citrulline by adding ammonia, carbon dioxide and removing water.
Citrulline converted into Arginine by adding ammonia and removing water.
Arginine converted back into ornithine by adding water; removing urea as a by-product.