The graph that follows shows the survival of four different E. coli strains after exposure to increasing doses of ultraviolet light. The wild-type strain is normal, but the other strains have a mutation in either a gene called uvrA, a gene called recA, or both. (b) What are the relative contributions of these genes to the repair of UV damage?

Verified step by step guidance

1. Identify the wild-type strain and note its survival rate across different UV doses.
2. Observe the survival rates of the uvrA, recA, and uvrA and recA mutant strains.
3. Compare the survival rates of the mutant strains to the wild-type strain to determine the impact of each gene mutation.
4. Analyze the differences in survival rates between the uvrA and recA mutants to understand the relative contributions of each gene.
5. Conclude that both uvrA and recA genes are important for UV damage repair, with the double mutant showing the lowest survival, indicating a synergistic effect.