The sensory nerves from mechanoreceptors are large myelinated Aα and Aβ fibers whose conduction velocities range from ∼70–120 & ∼40–75 m/s, respectively.

TLS Online TPP Program

#Id: 7444

#Unit 5. Developmental Biology

gp 80 – form tight aggregate

TLS Online TPP Program

#Id: 4760

#Unit 5. Developmental Biology

Embryos lacking PAL-1 have no somatic cell types derived from the C and D stem cells.

TLS Online TPP Program

#Id: 9203

#Unit 11. Evolution and Behavior

Balance natural selection

Balancing selection is a type of natural selection that maintains genetic diversity in a population.

In balancing selection, two or more alleles are kept in balance, and therefore are  maintained in a population over the course of many generations.

TLS Online TPP Program

#Id: 10331

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 2351

#Unit 5. Developmental Biology

If the planarian is cut in half, the anterior portion of the lower half regenerates a head while the posterior of the upper half regenerates a tail.