Clement’s organismic model- Competition causes sharp boundaries between groups of species; certain species group together.

TLS Online TPP Program

#Id: 2375

#Unit 5. Developmental Biology

 Wnt signaling achieves its repression of head regeneration by inhibiting Erk

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#Id: 2376

#Unit 5. Developmental Biology

Regulation of the balance between Wnt and Notum signals underlie not only head-tail specification but also regulation of organ size.

 

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#Id: 2377

#Unit 5. Developmental Biology

Two distinct populations of neoblasts exist:

1. Sigma neoblast population 

2. Zeta neoblast population 

TLS Online TPP Program

#Id: 3799

#Unit 5. Developmental Biology

Dictyostelia (social amoebas)

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#Id: 3800

#Unit 5. Developmental Biology

Dictyostelium can utilize one of three survival strategies when food starvation-

Microcyst formation, favoured in dark & wet conditions, or ammonia levels are high.

Zygote formation, favoured in dark & wet conditions, & is triggered by ethylene produced by the cells. 

Cell aggregation & differentiation

TLS Online TPP Program

#Id: 3801

#Unit 5. Developmental Biology

Cell Aggregation & Differentiation is common to all Dictyostelids.

It consists of an interconnected programme of cell movement and cell differentiation.