The elongation of the primitive streak coextensive with the anterior migration of secondary hypoblast cells, and hypoblast directs the movement of the primitive streak.

TLS Online TPP Program

#Id: 7689

#Unit 1. Molecules and their Interaction Relevant to Biology

                                         Zinc Finger Motif

 


TLS Online TPP Program

#Id: 9106

#Unit 10. Ecological Principles

Invasive species An introduced species that spreads rapidly and has negative effects on other species, human recreation, or human economies. 

TLS Online TPP Program

#Id: 3012

#Unit 3. Fundamental Processes

A helicase usually initiates unwinding at a single-stranded region adjacent to a duplex. Note that it cannot unwind a segment of duplex DNA; it can only continue to unwind a sequence that has been started.

TLS Online TPP Program

#Id: 5983

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 3510

#Unit 2. Cellular Organization

Mutations occur at the same rate in both exons and introns, but exon mutations are eliminated more effectively by selection.