B-cell survival in the follicle is dependent on access to the TNF-family member cytokine B-cell activation factor (BAFF), otherwise known as B lymphocyte survival factor (BLyS), which is secreted by the FDCs.

TLS Online TPP Program

#Id: 9572

#XL - T Zoology

The Forces of Evolution

Mutation, 

Genetic drift

Gene flow or migration

Selection

TLS Online TPP Program

#Id: 9921

#XL - T Zoology

Cell-Mediated Immunity against Virus

Both CD8+ TC cells and CD4+ TH1 cells are required components of the cell-mediated antiviral defense.

Activated TH1 cells produce IL-2, IFN-ϒ, and tumor necrosis factor-α.

TLS Online TPP Program

#Id: 8127

#XL - Q Biochemistry

β-Carotene is the precursor of vitamin A1.
Oxidation at C-15 converts retinol to the aldehyde, retinal, and further oxidation produces retinoic acid, a hormone that regulates gene expression. 

TLS Online TPP Program

#Id: 8001

#XL - T Zoology

Overlapping of fundamental niche

TLS Online TPP Program

#Id: 8868

#XL - R Botany