Final answer:
Synthesis-dependent strand annealing (SDSA) and double-strand break (DSB) repair homologous recombination are two mechanisms used by cells to repair DNA damage. SDSA is used in mating-type switching in yeast, while DSB repair homologous recombination is involved in repairing DNA damaged by single or double stranded breakage.
Step-by-step explanation:
Synthesis-dependent strand annealing (SDSA) and double-strand break (DSB) repair homologous recombination are two mechanisms used by cells to repair DNA damage. Both processes involve the use of homologous DNA templates to accurately repair the damaged DNA without deletions.
In SDSA, a single DNA strand nicked during replication is repaired by recombination with the complementary strand of another piece of homologous DNA. This process is used in mating-type switching in yeast.
In DSB repair homologous recombination, a double-stranded DNA break is repaired using the same recombination machinery that operates on sister chromatids in meiosis. This process is involved in repairing DNA damaged by single or double stranded breakage.
Overall, SDSA and DSB repair homologous recombination both play important roles in maintaining the integrity of the DNA and ensuring accurate repair.