Edexcel GCE Biology Unit 4 6BI04 June 2013

Thats really good thanks! from what I understand from Post transcriptional change is that. There intros (the parts that dont code for DNA) are spliced out which leaves the extons so you get a strand of mRNA. the exons are joined together in different orders to form different mRNA strands. This means that more than on amino acid sequence can form more than one protein..

The order of the exons doesn't change, but the number does. For example, if there were three exons in the pre-mRNA strand; 1,2 and 3, they could join together as 123, 12, 13 or 23, but NOT as 312 or 32 etc. Not sure if you meant this, but better safe than sorry.

Also, I don't know how useful this is but I've attached some of my revision posters for this exam...

Also if its not too much to ask would you mind making something similar for the antibiotics effectiveness experiment?

If two organisms can interbreed to produce a hybrid, which is not fertile, are these two organisms of the same species? If not, why?

If two organisms can interbreed to produce a hybrid, which is not fertile, are these two organisms of the same species? If not, why?

well, i'm gonna fail. :/ i'm resitting from january and i appear to have forgotten everything. so any tips to cramming??

In the syllabus it says we need to know about the storing of hydrogen in a fuel by combining it with carbon dioxide and realeaseing oxygen into the atmosphere..what does that mean?

In the syllabus it says we need to know about the storing of hydrogen in a fuel by combining it with carbon dioxide and realeaseing oxygen into the atmosphere..what does that mean?

can anyone help me please?
i keep getting D's in all the past papers i'm doing, what can i do to improve my grade?
thank you