The ability of any stem cell to self-renew and differentiate depends on the structural organization and cellular function of specialized anatomic microenvironments known as stem cell niches. These sequestered regions are typically populated by a supportive network of stromal cells. Stem cell niche stromal cells express soluble and membrane-bound proteins that regulate cell survival, proliferation, differentiation, and trafficking. Which statements is true about HSCs?

#Question id: 4660

#Unit 3. Fundamental Processes

Two-component system regulating response to low Gln,

a) Glutamine dissociates from the sensor domain in the NtrB protein, leading to activation of a histidine kinase transmitter domain in NtrB

b) glutamine binds to a sensor domain of NtrB, causing a conformational change in the protein that inhibits its histidine kinase activity, the regulatory domain of NtrC blocks its DNA-binding domain from binding the glnA enhancers.

c) Activated transmitter domain of NtrB that transfers the γ-phosphate of ATP to a histidine residue (H), this phosphohistidine then transfers the phosphate to an aspartic acid residue (D) in the NtrC protein

d) This causes a conformational change in NtrC that unmasks the NtrC DNA-binding domain so that it can bind to the glnA enhancers

Which of the following combination is correct?

#Question id: 12651

#Unit 6. System Physiology – Plant

#Question id: 310

#Unit 1. Molecules and their Interaction Relevant to Biology

Ionic bonds easily form when electron when ionization energy of the metallic atom is _____ comparatively.

#Question id: 11209

#Unit 7. System Physiology – Animal

Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium/potassium channel and opens it. This is an example of ________.

#Question id: 4558

#Unit 3. Fundamental Processes

Classes of RNA transcribed by the three eukaryotic nuclear RNA Polymerase;

 Match the following correct combination given above combinations;