In the absence of gibberellin, the DELLA proteins positively regulate GID1, GA20ox, and GA3ox (plus signs), and negatively regulate GA2ox (minus sign). Conversely, both bioactive gibberellin and the GID1 receptor enhance DELLA repressor degradation (plus signs), while GA2ox blocks DELLA repressor degradation (minus signs).

TLS Online TPP Program

#Id: 7582

#Unit 5. Developmental Biology

The membrane potential of the sperm cell becomes more negative as potassium ions leave the sperm. 

TLS Online TPP Program

#Id: 1749

#Unit 4. Cell Communication and Cell Signaling

Corticosteroids and prostaglandins can also decrease expression of class II MHC molecules.

TLS Online TPP Program

#Id: 9471

#Unit 4. Cell Communication and Cell Signaling

STAT5 becomes activated in erythroid progenitor cells and induces expression of the protein Bcl-xL.

TLS Online TPP Program

#Id: 2787

#Unit 13. Methods in Biology

The length of column containing one theoretical plate is referred to as the plate height, H, which has units of length normally in micrometers.

TLS Online TPP Program

#Id: 5819

#Unit 7. System Physiology – Animal

The renal epithelial cells express the enzyme 11β-HSD2, which prevent cortisol from activating mineralocorticoid receptors.