Some of the regions in the eye lack color, whereas others are red. This is because the white gene (required to develop red pigment) was inactivated by adjacent heterochromatin in some cells, but remained active in others.

TLS Online TPP Program

#Id: 8427

#Unit 10. Ecological Principles

Principle of allocation - The observation that when resources are devoted to one body structure, physiological function, or behavior, they cannot be allotted to another. 

TLS Online TPP Program

#Id: 949

#Unit 5. Developmental Biology

Sperm-specific calcium channels are encoded by CatSper genes

TLS Online TPP Program

#Id: 9547

#Unit 11. Evolution and Behavior

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: 6069

#Unit 10. Ecological Principles