In cytokine receptors, 

the receptor and kinase are separate polypeptides, encoded by different genes, yet are bound tightly together.

TLS Online TPP Program

#Id: 1893

#Unit 4. Cell Communication and Cell Signaling

Superantigens

Viral or bacterial proteins that bind simultaneously to the Vβ domain of a T-cell receptor and to the α chain of a Class II MHC molecule

TLS Online TPP Program

#Id: 1038

#Unit 5. Developmental Biology

Anencephaly 

a failure of the anterior (rostral) portion of the embryonic neural tube (anterior neuropore) to close properly.

OR

a failure to close the neural tube allows the forebrain to remain in contact with amniotic fluid and subsequently degenerate.

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#Id: 6885

#Unit 3. Fundamental Processes

DNA methylation and macroH2A contribute to the stable repression of the inactive X chromosome  A. Wutz and J. Gribnau, Curr. Opin. Genet. Dev. 17 (2007): 387–393. inactive specific transcript), which is stably expressed only on the inactive X chromosome.

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#Id: 8637

#Unit 2. Cellular Organization

The G1 cyclin-CDK complex (Cln3-CDK in yeast) stimulates the formation of G1/S phase cyclin-CDKs, which initiate bud formation, centrosome duplication, and DNA replication.

TLS Online TPP Program

#Id: 9901

#Unit 4. Cell Communication and Cell Signaling