Unpaired protein activates the JAK-STAT pathway in the adjacent germ stem cells to specify their self-renewal

TLS Online TPP Program

#Id: 10291

#Unit 4. Cell Communication and Cell Signaling

The second phase of T-cell development

1.Positive selection: Selection for those cells whose T-cell receptors engage self-MHC.

2.Negative selection: Selection against those cells whose T-cell receptors bind too strongly to self-peptide/MHC combinations.

3.Lineage commitment: Commitment of thymocytes to effector cell lineages, including CD4 helper or CD8 cytotoxic populations

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#Id: 941

#Unit 5. Developmental Biology

 The mode of fertilization in sea urchin being external, the egg and spermatozoa are released into the sea water.

TLS Online TPP Program

#Id: 1593

#Unit 5. Developmental Biology

Hensen’s node is the functional equivalent of the organizer (dorsal lip of the amphibian blastopore)

TLS Online TPP Program

#Id: 4798

#Unit 13. Methods in Biology

Mean deviation: It is the mean of the absolute values of the numerical differences between the numbers of a set and their mean or median.

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#Id: 2368

#Unit 5. Developmental Biology

Loss of the zeta population 

Epidermal cell types do not fully regenerate in the absence of zeta neoblasts, the remaining neoblasts (likely sigma) and their derived cell types are unaffected.