From the four possible transitions (n!p*, p!p*, n!s*, s!s*), only two can be elicited with light from the UV/Vis spectrum for some biological molecules: n!p* and p!p*. The n!s* and s!s* transitions are

energetically not within the range of UV/Vis spectroscopy and require higher energies.

TLS Online TPP Program

#Id: 7009

#Unit 5. Developmental Biology

Adult stem cells must maintain the long-term ability to divide, be able to produce some differentiated daughter cells, and still repopulate the stem cell pool.

TLS Online TPP Program

#Id: 7010

#Unit 5. Developmental Biology

Precise control of the division and differentiation of stem cell types is necessary for building the embryo as well as maintaining and regenerating tissues in the adult. progenitor differentiation through endocrine, paracrine, or juxtacrine mechanisms.

TLS Online TPP Program

#Id: 7011

#Unit 5. Developmental Biology

Regulation is highly influenced by the microenvironment that surrounds a stem cell and is known as the stem cell niche.

TLS Online TPP Program

#Id: 7012

#Unit 5. Developmental Biology

All tissue types possess a unique stem cell niche, and despite many differences among the niche architecture of different tissues

TLS Online TPP Program

#Id: 7013

#Unit 5. Developmental Biology

All tissue types possess a unique stem cell niche, and despite many differences among the niche architecture of different tissues.

TLS Online TPP Program

#Id: 7014

#Unit 5. Developmental Biology

The types of the intracellular mechanisms used by a given stem cell are in part the downstream net result of the extracellular stimuli in its niche.