The emerging column of cells topples over called ‘the slug’.

TLS Online TPP Program

#Id: 4738

#Unit 5. Developmental Biology

The anterior-posterior axis is determined before the first cell division, and the cleavage furrow is located asymmetrically along this axis of the egg, closer to what will be the posterior pole.

TLS Online TPP Program

#Id: 4739

#Unit 5. Developmental Biology

The stem cell lineage always undergoes meridional ,division to produce

(1) An anterior founder cell (AB)

(2) A posterior cell (P1) that will continue the stem cell lineage.

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#Id: 4740

#Unit 5. Developmental Biology

The founder cell (AB) divides equatorially, while the P1 cell divides meridionally (transversely) to produce another founder cell (EMS) and a posterior stem cell (P2).

TLS Online TPP Program

#Id: 4741

#Unit 5. Developmental Biology

The decision of the anterior and posterior axis depends on the position of the sperm pronucleus in egg.

TLS Online TPP Program

#Id: 4742

#Unit 5. Developmental Biology

C. elegans oocyte use the “partitioning-defective,” or PAR proteins, in establishing cell polarity. 

TLS Online TPP Program

#Id: 4743

#Unit 5. Developmental Biology

Cortical cytoplasm contains PAR-3, PAR-6 & PKC-3 Internal cytoplasm contains PAR-2 and PAR-1