Primary neurulation can be divided into four stages:

1. Elongation and folding of the neural plate

2. Bending of the neural plate

3. Convergence of the neural folds

4. Closure of the neural tube

TLS Online TPP Program

#Id: 1677

#Unit 4. Cell Communication and Cell Signaling

Adjuvants are substances added to vaccine preparations that help aid in delivery of the vaccine to the immune system and that enhance responses.

TLS Online TPP Program

#Id: 1678

#Unit 4. Cell Communication and Cell Signaling

Multiple gene segments exist at heavy (V, D, and J) and light-chain (V and J) loci.

TLS Online TPP Program

#Id: 1679

#Unit 4. Cell Communication and Cell Signaling

Junctional diversity- P and N nucleotides  addition

TLS Online TPP Program

#Id: 1680

#Unit 4. Cell Communication and Cell Signaling

P nucleotide addition results when the DNA hairpin at the coding joint is cleaved asymmetrically.

TLS Online TPP Program

#Id: 1681

#Unit 4. Cell Communication and Cell Signaling

Non - templated N nucleotide addition in heavy chains results from TdT activity.

TLS Online TPP Program

#Id: 1682

#Unit 4. Cell Communication and Cell Signaling

Exonuclease trimming sometimes occurs at the VDJ and VJ junctions, causing loss of nucleotides.