during the process of self-replication what would happen
a) if rna did not self-replicate
b) if dna did not replicate?
c) if dna replicated but it could not be transcribed?

Question

during the process of self-replication what would happen 
a) if rna did not self-replicate
b) if dna did not replicate?
c) if dna replicated but it could not be transcribed?

miracrown · Answer

Let's take a look at Scenario A first ...

miracrown · Answer

RNA was once thought to be the nucleic acid that was the basis of all life, not DNA
It's still very vital to the functioning of our bodies, especially when it comes to translating proteins. Without self-replicating RNA, you might see a case where there may not be enough expression of a certain RNA transcript.

People assume that RNA is only used to make proteins. That's mRNA that is used to translate proteins.
mRNA = messenger RNA. But we also need tRNA (transfer RNA) and rRNA (ribosomal RNA)
If they did not self-replicate, we would not have translation at all.

miracrown · Answer

Scenario B) if DNA did not replicate

DNA replication serves one major purpose--to help distribute genetic material from one "parent" cell to two "daughter" cells. It occurs prior to cell division. Cells need genetic material so that they can perform essential tasks, such as expressing genes that will help them grow and remain healthy.

If DNA could not replicate, then cells wouldn't need to divide, and if cells can't divide, then genetic material would not be passed down from generation to generation.

miracrown · Answer

Scenario C) if DNA replicated but it could not be transcribed

As I wrote earlier, cell division relies on the ability of DNA to be replicated. So as long as DNA can be replicated, cells will divide. 

But, I also touched on the fact that the genetic material has to be transcribed and later translated into proteins that will help the cell grow and carry out other metabolic functions. So having the genetic material is nice and all, but it's meaningless if you can't actually use it. Eventually, the cells will die because they cannot create the proteins they need to grow/perform metabolic processes.

For example, many cells require glucose as a fuel source. Without proteins that help them break down the glucose into ATP, they will starve.

anonymous · Answer

I get it now. Thank you so much!!