can you check my answer to #4 4. (1) Microbial transmission of disease The colitogenic bacteria that caused ulcerative colitis in RAG-1 knock-out mice could be transmitted to healthy mice. It led to T-bet not functioning which will induce production of TNF alpha, where it causes growth of Colitogenic bacteria. When these knock-out mice were incubated with healthy mice, these colitogenic bacteria were passed to healthy ones, resulting in the same disease. This supports microbial transmission of disease. (2) role of innate immunity in controlling microbial balance The mutation in T-bet, a gene involved in cytokine regulation in dendritic cells, led to uncontrolled inflammation (too much TNF alpha) and overgrowth of colitogenic bacteria. It showed how innate immune dysfunction can lead to microbiome imbalance and chronic inflammatory disease, even without adaptive immunity.