The primitive streak defines the major body axes of the avian embryo. 

TLS Online TPP Program

#Id: 7942

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 6492

#Unit 3. Fundamental Processes

Binding of the TFIID complex in the initiation reaction regularly protects the region from -45 to -10.

TLS Online TPP Program

#Id: 6148

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 177

#Unit 5. Developmental Biology

In Permissive interaction

The responding tissue has already been specified and needs only an environment that allows the expression of these traits. 

TLS Online TPP Program

#Id: 473

#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.