Question

Guardian angel of the genome is
(A) PRB
(B) p53 protein
(C) T4 cell
(D) Interleukin-I

Answer 1

Hint: Guardian angel of the genome is that protein acts as a tumor suppressor, which means that it regulates cell division by keeping cells from growing and dividing (proliferating) too fast or in an uncontrolled way.

Complete answer:
The p53 protein is considered the guardian angel of the cell's genome. It plays a crucial role at the G1 checkpoint within the regulation of the cell division cycle. It guards the integrity of the DNA.
The protein is existing at a lower density within the cell. When the protein remains present in higher concentration, the cellular division is ceased and therefore the cell faces apoptosis.
If there's some mutation that may be mended, the correction is implanted.
The name p53 of this protein was given in the year 1979 telling about its apparent molecular mass; SDS-PAGE analysis indicates that it's a 53-kilodalton (kDa) protein. However, the particular mass of the full-length p53 protein (p53α) supporting the sum of masses of the amino acid residues is merely 43.7 kDa. Also, the human TP53 gene encodes a minimum of 15 protein isoforms, ranging in size from 3.5 to 43.7 kDa. These p53 proteins are called the p53 isoforms. The TP53 gene is the most often mutated gene (>$50\%$) in human cancer, indicating that the TP53 gene plays an important role in preventing cancer formation. The TP53 gene encodes the type of proteins that bind to the molecule of the DNA and regulate organic phenomenon to stop mutations of the genome.

So, the correct answer is ‘p53 protein’.

Note:
The type of mutations that inactivate p53 in cancer usually occurs within the DBD. Most of those mutations destroy the power of the protein to bind to its target DNA sequences, and thus prevents transcriptional activation of those genes. As such, mutations within the DBD are recessive loss-of-function mutations.