Ans.
Gene regulation or regulation of gene expression involves mechanisms, used by the cells to enhance or reduce the expression of specific genes to make proteins or RNA. Gene regulation occurs at transcriptional level and post-transcriptional level, which involves regulation at translational level or protein level.
Regulation at translational level or protein level is also important as regulation at transcriptional level. Translational regulation controls formation of proteins from mRNA molecules and includes non-coding mRNAs and repressor proteins. It is important for cell growth, differentiation and cellular response to stress and provides an immediate adjustment of gene expression by directly regulating the protein concentration.
Regulation at protein level involves regulation of active protein. It includes regulation by various small molecules, post-translational modifications (such as phosphorylation), and proteolysis. Regulation only at transcriptional level is not sufficient to provide proper gene regulation and leads to various drawbacks, such as Fragile X Syndrome (due to defect in a protein).
Thus, 'gene regulation is important both at transcriptional level and at post-transcriptional level (during translation or protein level).'
The correct answer is "ovulation" and "corpus luteum" respectively. In ovulation, the egg ruptures from the mature follicle (called the Graafian follicle). This process is preceded by the sudden rise in luteinizing hormone. The follicle now becomes the corpus luteum, actually does not secrete estrogen, it secretes progresterone which prepares the uterine lining for pregnancy.
