Character displacement

Morphological differences in two closely related species present in same geographical area while similar morphology when present at different geographical are

1. Niche diversification

2. Co-existence of many species

3. Evolutionary program

TLS Online TPP Program

#Id: 1031

#Unit 5. Developmental Biology

In secondary neurulation, 

the neural tube arises from the aggregation of mesenchyme cells into a solid cord that subsequently forms cavities that coalesce to create a hollow tube.

 

TLS Online TPP Program

#Id: 1032

#Unit 5. Developmental Biology

Primary neurulation forms the anterior portion of the neural tube

TLS Online TPP Program

#Id: 1033

#Unit 5. Developmental Biology

Secondary neurulation forms the posterior portion of the neural tube 

TLS Online TPP Program

#Id: 1034

#Unit 5. Developmental Biology

In birds, primary neurulation generates the neural tube anterior to the hindlimbs.

TLS Online TPP Program

#Id: 1035

#Unit 5. Developmental Biology

In mammals, secondary neurulation begins at the level of the sacral vertebrae of the tail.

TLS Online TPP Program

#Id: 1036

#Unit 5. Developmental Biology

Junctional neurulation 

combination of mechanisms involved in both primary and secondary neurulation