To prevent oxidative damage by • O2 2 , cells have several forms of the enzyme superoxide dismutase, which catalyzes the formation of hydrogen peroxide (H2O2)

TLS Online TPP Program

#Id: 6698

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 8820

#Unit 6. System Physiology – Plant

TLS Online TPP Program

#Id: 1760

#Unit 4. Cell Communication and Cell Signaling

Self-tolerance involving both the elimination of immune cells that can react against self-antigens and active inhibition of immune responses.

TLS Online TPP Program

#Id: 6886

#Unit 3. Fundamental Processes

Recruitment of Polycomb repressor complexes (PRC1 and PRC2), which trigger a series of chromosome-wide histone modifications (H2AK119 ubiquitination, H3K27 methylation, H4K20 methylation, and H4 deacetylation). Late in the process, an inactive X-specific histone variant, macroH2A

TLS Online TPP Program

#Id: 3189

#Unit 3. Fundamental Processes

Some mitochondrial DNAs possess several D loops, reflecting the use of multiple origins. The same mechanism is employed in chloroplast DNA, where (in complex plants) there are two D loops.