Question

!!! One Medal Question !!!

Answer 1

- How may mRNA be modified before it leaves the nucleus?

- Outline the steps of translation.

- Define mutation and mutagen.

Answer 2

@Zale101

Answer 3

@blues

Answer 4

@thomaster @aaronq

Answer 5

The mRNA needs to be processed to
protect from degradation (5'cap and polyadenylation)
splicing - Remove intronic sequences which should not be coded and the exons joined
Attachment of various proteins to the mRNA to specify certain signals such as .... hnRNP binds only to intronic sequences , so if there are hnRNP still bound, thats a message to say that proper splicing has not occured and this will be a signal for the cell to degrade this mRNA sequence. Also there are proteins that binds to exons to specify that they are correct exons and also proteins that aids in exporting the mRNA from the nucleus to the cytoplasm and then once in the cytoplasm a new set of proteins will be bound to signal that the mRNA is ready for translation.
All these needs to happen ... if there is a mistake in any sequence ... the mRNA degradation mechanisms will take into effect (sensing its a bad mRNA) and will degrade it.

Answer 6

Design an Experiment: What is the independent variable in this experiment (i.e., the variable that you manipulate)?