The number of Na + channels per square micrometer of membrane in myelinated mammalian neurons has been estimated: 

50–75 in the cell body, 350–500 in initial segment, less than 25 on the surface of the myelin, 2000–12,000 at the nodes of Ranvier & 20–75 at the axon terminals 

TLS Online TPP Program

#Id: 1250

#Unit 7. System Physiology – Animal

Posterior pituitary secretes neuropeptides, ADH and oxytocin

TLS Online TPP Program

#Id: 4761

#Unit 5. Developmental Biology

PAL-1 is regulated by the MEX-3 protein, an RNA binding protein that inhibit the translation of pal-1 mRNA.

TLS Online TPP Program

#Id: 3515

#Unit 2. Cellular Organization

A mutation that confers a more advantageous phenotype to an organism, relative to Individuals in the same population without the mutation, is positive selection of that organism.

TLS Online TPP Program

#Id: 7971

#Unit 10. Ecological Principles

Osmosis is the movement of water across membranes to balance solute concentrations. Water diffuses from a solution that is hypotonic into a solution that is hypertonic

Turgor pressure is the hydrostatic pressure that increases as water enters plant cells.

TLS Online TPP Program

#Id: 6675

#Unit 3. Fundamental Processes

Lariat formation is characterize by 2’-5’ phosphodiester bond Prp8, a large scaffold protein that directly contacts both the 5’ and 3’ splice sites within the spliceosome.