The characteristic absorption parameter for the sample is the extinction coefficient a, yielding the correlation I= I0e-ad.

TLS Online TPP Program

#Id: 1037

#Unit 5. Developmental Biology

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: 1038

#Unit 5. Developmental Biology

Anencephaly 

a failure of the anterior (rostral) portion of the embryonic neural tube (anterior neuropore) to close properly.

OR

a failure to close the neural tube allows the forebrain to remain in contact with amniotic fluid and subsequently degenerate.

TLS Online TPP Program

#Id: 1039

#Unit 5. Developmental Biology

Craniorachischisis-combination of anencephaly with a contiguous bony defect of the spine (also without meninges covering the neural tissue –rachischisis)

TLS Online TPP Program

#Id: 1040

#Unit 5. Developmental Biology

The first visible sign of limb development is the formation of bilateral bulges called limb buds.

1. limb bud  is 

TLS Online TPP Program

#Id: 1041

#Unit 5. Developmental Biology

The cells that make up the limb bud are derived from the 

1. posterior lateral plate mesoderm

2. adjacent somites

3. bud’s overlying ectoderm

TLS Online TPP Program

#Id: 1042

#Unit 5. Developmental Biology

Limb field - All the cells are capable of forming a limb on their own.