Question

A) List one type of error-prone DNA repair mechanism (which routinely introduces errors into the repaired DNA) and list the type of DNA damage repaired. B) List one DNA repair mechanism that generally corrects the DNA damage without error, and list the type of DNA damage repaired.

Answer 1

Answer A

The mechanism or process that repairs severely damaged bases in DNA occurs by the base excision or replacement is termed as a DNA repair mechanism.   

The SOS response is an error-prone repair system that responds to DNA damage. In this process, the cell cycle is arrested and DNA repair induced by RecA protein that is stimulated by single-stranded DNA.

Answer B

The DNA damage is an alteration in DNA that can lead to cellular injury and decrease the viability or reproductive health of the individual. The various types of DNA repair mechanisms like direct repair, base excision repair, nucleotide excision repair (NER) and double-strand break repair. Base excision repair (BER) is a mechanism that repairs damaged DNA throughout the cell cycle.

Type of DNA Damage

1. Deletions

Deletion damage is the caused due to the frameshift that leads to loss of base-pair from DNA. A deletion of three or more bases leads to an intact reading frame. A deletion of codons leads to missing of protein and amino acids.

2. Insertions

The insertion damage is the additional base pairs that may be frameshifts depending. The new base pairs are inserted in this type of damage.