Central dogma of Biology is - DNA to RNA to Protein. The gene expression is controlled by gene regulation.
Explanation:
a) Two reasons why gene regulation must be regulated in eukaryotes are :
i. To remove the introns which are the non coding regions of the mRNA segment and make mature mRNA that will code for proteins.
ii. Gene regulation increases the flexibility and adaptability of a life form by permitting the cell to code for protein when required.
b) Three processes that regulate gene expression in eukaryotes are:
i. Transcription - Transcription is a main regulatory point for several genes. Group of transcription factors stick to specific DNA sequences in or around a gene and promote or repress its transcription into an RNA.
ii. RNA processing - cutting, capping, and poly-A tail addition to an RNA molecule can be regulated which can then exit from the nucleus. Various mRNAs can be made from the same pre-mRNA by the process of alternative splicing. Removal of introns also makes mRNA activated.
iii. Translation - Translation of an mRNA can be enhanced or inhibited by regulators. For example- miRNAs occasionally inhibit translation of their target mRNAs, instead of removing them.