Class II MHC glycoproteins expressed predominantly on pAPCs, where they primarily present exogenous antigenic peptides to CD4+ T cells.

TLS Online TPP Program

#Id: 7761

#Section 2: General Biology

A covalent bond is a chemical bond that occurs when two or more atoms share electrons. The sharing of electrons helps complete the outer shell, or valence shell, of both atoms. The sharing of electrons creates a stable balance of attractive and repulsive forces between atoms.

TLS Online TPP Program

#Id: 9280

#Section 2: General Biology

The interaction between NFR and SYMRK initiates calcium spiking in the nucleus, presumably via a second messenger molecule.

Core symbiotic genes are activated.

Cytokinin signaling is initiated.

TLS Online TPP Program

#Id: 8872

#Section 3: Genetics, Cellular and Molecular Biology

The entire process of mitotic CDKs activation and entry into mitosis involves two positive feedback loops and coordination between events at the centrosome, in the cytoplasm, and in the nucleus.

TLS Online TPP Program

#Id: 10318

#Section 2: General Biology

Cytotoxic T cells release granules containing the proteins perforin and granzyme-B. 

TLS Online TPP Program

#Id: 9183

#Section 3: Genetics, Cellular and Molecular Biology

The selection gradient measures the strength of directional selection acting on a quantitative trait.